These are the positive integers used for counting. N = {1,2,3,4,…}
Real Numbers (R)
This set includes all rational and irrational numbers. It encompasses all numbers that can be represented on a number line.
Rational Numbers (Q)
These numbers can be expressed as a fraction p/q, where p and q are integers and q ≠ 0. They include:
All integers (e.g., -3, 0, 5).
Terminating decimals (e.g., 0.25).
Repeating decimals (e.g., 0.333...).
Irrational Numbers (I)
These numbers cannot be expressed as a fraction p/q. They have non-terminating, non-repeating decimal expansions. Examples:
√2 (square root of 2).
π (pi).
e (Euler's number).
Approximation (Rounding Off)
Rounding Off to a Required Decimal Place
Rule: If the digit following the desired decimal place is 5 or greater, round the preceding digit up. If the digit following the desired decimal place is less than 5, leave the preceding digit as it is.
Examples:
Round 3.14159 to 2 decimal places: The digit after the second decimal place (4) is 1. Therefore, 3.14159 rounds to 3.14.
Round 12.789 to 1 decimal place: The digit after the first decimal place (7) is 8. Therefore, 12.789 rounds to 12.8.
Round 0.9997 to 3 decimal places: The digit after the third decimal place (9) is 7. Therefore, 0.9997 rounds to 1.000.
Rounding Off to a Required Significant Figure
Rules:
All non-zero digits are significant.
Zeros between non-zero digits are significant.
Trailing zeros in a number with a decimal point are significant.
Leading zeros are not significant.
If the next number is 5 or greater, round up, otherwise round down.
Examples:
Round 12345 to 3 significant figures: The first three significant figures are 123. The next number is 4, so we round down. Therefore, 12345 rounds to 12300.
Round 0.005678 to 2 significant figures: The first two significant figures are 56. The next number is 7, so we round up. Therefore, 0.005678 rounds to 0.0057.
Round 3.14159 to 4 significant figures: The first four significant figures are 3.141. The next number is 5, so we round up. Therefore, 3.14159 rounds to 3.142.
Round 10.05 to 3 significant figures: The first three significant figures are 10.0. The next number is 5, so we round up. Therefore, 10.05 rounds to 10.1.
Round 1005 to 3 significant figures: The first three significant figures are 100. The next number is 5, so we round up. Therefore, 1005 rounds to 1010.
Repeated division: Divide the decimal number by the target base, noting the remainders. The remainders, read in reverse order, form the number in the new base.
Other Bases to Decimal:
Positional notation: Multiply each digit by the base raised to the power of its position (starting from 0 on the right), and then sum the results.
Example Conversions
Let us convert the decimal number 250 to binary, octal, duodecimal, and hexadecimal.
2 = 010
6 = 110
2 = 010
Combine the binary representations: 010 110 010
Binary result: 010110010 (or 10110010, removing the leading zero)
3. Octal (262) to Hexadecimal
Group the octal digits into groups of four, starting from the right. If needed, add leading zeros:
0262 (group the numbers as if they were binary numbers, and then use the octal to binary conversion, and group the binary into 4 bit sections.)
010110010 (binary equivalent)
0101 1001 0 (group into sets of 4)
0101 1001 (remove the last zero)
Convert each 4-bit group to hexadecimal:
0101 = 5
1001 = 9
Hexadecimal result: 59
Example 2: Convert Decimal 350 to Octal, Binary, and Hexadecimal
Group the octal digits into groups of four, starting from the right:
1010 11110 (binary equivalent of 536)
1 0101 1110 (add a leading zero, and group into sets of 4)
Convert each 4-bit group to hexadecimal:
0001 = 1
0101 = 5
1110 = E
Hexadecimal result: 15E
Fundamental Mathematical Laws
1. Cumulative Laws (Commutative Laws)
Definition: These laws state that the order of operands doesn't affect the result for certain operations.
Addition: a + b = b + a Multiplication: a × b = b × a
Application:
Simplifying expressions: If you have 3 + 5 + 7, you can rearrange it as 5 + 3 + 7 or 7 + 3 + 5 without changing the sum.
Mental math: When calculating 8 × 7, you might find it easier to think of it as 7 × 8.
Definition: These laws state that the grouping of operands doesn't affect the result for certain operations.
Addition: (a + b) + c = a + (b + c) Multiplication: (a × b) × c = a × (b × c)
Application:
Simplifying complex expressions: When you have a chain of additions or multiplications, you can group them in a way that makes the calculation easier.
Example:
Problem: Calculate 2 × (5 × 9) Solution: Using the associative law, you can also calculate (2 × 5) × 9 = 10 × 9 = 90. Or you can calculate 2 × 45 = 90.
3. Distributive Law
Definition: This law describes how multiplication distributes over addition (or subtraction).
a × (b + c) = (a × b) + (a × c) a × (b - c) = (a × b) - (a × c)
Application:
Expanding expressions: It's used to multiply a single term by multiple terms within parentheses.
Factoring expressions: It's also used in reverse to factor out a common factor.
Mental math: It can help break down larger multiplications into smaller, more manageable ones.
Commutative: Order doesn't matter (addition, multiplication). Associative: Grouping doesn't matter (addition, multiplication). Distributive: Multiplication spreads over addition/subtraction.
BODMAS
When simplifying arithmetic expressions, it is crucial to follow the correct order of operations to ensure you arrive at the accurate answer. This order is commonly remembered using the acronym BODMAS (or PEMDAS in some regions). Here is a breakdown:
BODMAS stands for:
Brackets (or Parentheses)
Orders (or Exponents)
Division
Multiplication
Addition
Subtraction
Key Points:
Division and Multiplication have equal priority, and you perform them from left to right.
Addition and Subtraction also have equal priority, and you perform them from left to right.
How to apply BODMAS:
Brackets (Parentheses):
First, simplify any expressions within brackets (or parentheses). If there are nested brackets, start with the innermost ones.
Orders (Exponents):
Next, evaluate any orders (powers or exponents) like squares, cubes, etc.
Division and Multiplication:
Perform division and multiplication from left to right in the order they appear.
Addition and Subtraction:
Finally, perform addition and subtraction from left to right in the order they appear.
Example:
Let's simplify the following expression: 10 + 2 × (15 – 5) ÷ 4
Brackets:
15 - 5 = 10
The expression becomes: 10 + 2 × 10 ÷ 4
Multiplication and Division (from left to right):
2 × 10 = 20
The expression becomes: 10 + 20 ÷ 4
20 / 4 = 5
The expression becomes 10 + 5
Addition:
10 + 5 = 15
Therefore, the simplified expression is 15.
Importance:
BODMAS ensures consistency in mathematical calculations. Without a standard order, different people could arrive at different answers for the same expression.
It's a fundamental concept in mathematics that's essential for solving more complex equations and problems.
Equations
Definition of an Equation
An equation is a mathematical statement that asserts the equality of two expressions. It's characterized by an "equals" sign (=).
The expressions on either side of the equals sign are called the "left-hand side" (LHS) and the "right-hand side" (RHS).
The goal when working with equations is often to find the value(s) of the unknown variable(s) that make the equation true.
Constructing Equations of Letters and Numbers
Equations can involve numbers, variables (represented by letters like x,y,a,b), and mathematical operations (+, -, ×, ÷).
Examples:
Simple equation with one variable: 2x + 5 = 11
Equation with multiple variables: y = 3x - 2
Equation with only numbers: 7 + 3 = 10
Equation with fractions: x/2+ 5 = 9
Equation with exponents: x2+ 2 = 6
Building Equations:
Start with a relationship you want to express mathematically.
Represent unknown quantities with variables.
Use mathematical operations to connect the variables and numbers.
Ensure that the LHS and RHS are equal.
Rules of Equations (and Transposition)
The fundamental principle governing equation manipulation is that whatever you do to one side of the equation, you must do to the other side to maintain equality. This principle leads to the following rules:
Addition Property of Equality:
If a = b, then a + c = b + c (You can add the same value to both sides).
Subtraction Property of Equality:
If a = b, then a – c = b - c (You can subtract the same value from both sides).
Multiplication Property of Equality:
If a = b, then a × c = b × c (You can multiply both sides by the same value).
Division Property of Equality:
If a = b, then a ÷ c = b ÷ c (You can divide both sides by the same non-zero value).
Transposition
Transposition is a simplified way of applying these rules. It involves moving terms from one side of the equation to the other by changing their signs.
How Transposition Works:
If a term is added on one side, it becomes subtracted when moved to the other side.
If a term is subtracted on one side, it becomes added when moved to the other side.
If a term is multiplied on one side, it becomes divided when moved to the other side.
If a term is divided on one side, it becomes multiplied when moved to the other side.
Example:
Solve for x: x + 3 = 7
Using transposition: x = 7 - 3
Therefore, x = 4
Explanation of the steps.
We wanted to isolate x.
To do this we moved the +3 from the left hand side, to the right hand side.
When we moved the +3, it became a -3.
We then simply performed the subtraction of 7-3, to get 4.
Applying the Rules
Example 1: Solve for x: 2x – 5 = 9
Add 5 to both sides: 2x – 5 + 5 = 9 + 5
Simplify: 2x = 14
Divide both sides by 2: 2x / 2 = 14 / 2
Simplify: x = 7
Example 2: Solve for y: y / 3 + 1 = 4
Subtract 1 from both sides: y / 3 + 1 – 1 = 4 - 1
Simplify: y / 3 = 3
Multiply both sides by 3: (y / 3) × 3 = 3 × 3
Simplify: y = 9
Distinguishing Between Expressions and Equations
Expression:
An expression is a combination of numbers, variables, and mathematical operations.
It represents a value but doesn't state an equality.
Examples:
3x + 5
a2 - 2ab + b2
10 ÷ 2 + 4
Expressions can be simplified or evaluated, but they don't solve for a specific variable.
Equation:
An equation is a statement that two expressions are equal.
It always contains an equals sign (=).
Examples:
3x + 5 = 11
a2 - 2ab + b2 = 0
10 ÷ 2 + 4 = 9
Equations can be solved to find the value of the unknown variable(s).
Key Difference: The presence of an equals sign (=) is the defining characteristic that distinguishes an equation from an expression.
Relating Equations to Formulas
Formula:
A formula is a specific type of equation that expresses a relationship between two or more variables.
It's often used to calculate a specific quantity.
Formulas are typically used in science, engineering, and other fields to represent established relationships.
Examples:
Area of a rectangle: A = l × w
Speed: v = d / t
Ohm's Law: V = IR
Relationship:
All formulas are equations, but not all equations are formulas.
Formulas are equations that have a specific, established meaning and are used for practical calculations.
Essentially, a formula is an equation that represents a rule.
Transposing Formulas in Motor Vehicle Technology and Science
Transposition involves rearranging a formula to solve for a different variable.
Motor Vehicle Technology:
Formula: Torque (T) = Force (F) × Lever Arm (r)
If you need to find the force (F), transpose the formula: F = T / r
If you needed to find the lever arm (r), you would transpose the formula to: r = T / F
Formula: Power (P) = Torque (T) × Angular Velocity (ω)
If you need to find the torque (T), transpose the formula: T = P / ω
If you needed to find the angular velocity (ω), you would transpose the formula to: ω = P / T
Science (Physics):
Formula: Force (F) = mass (m) × acceleration (a)
If you need to find the acceleration (a), transpose the formula: a = F / m
If you need to find the mass (m), transpose the formula: m = F / a
Formula: Ohm's Law (Electrical Circuits): Voltage (V) = Current (I) × Resistance (R)
If you need to find the current (I), transpose the formula: I = V / R
If you need to find the resistance (R), transpose the formula: R = V / I
Formula: Kinematic Equation: v = u + at (final velocity = initial velocity + acceleration × time)
If you need to find acceleration (a):
v - u = at
a = (v - u) / t
If you need to find time (t): t = (v - u) / a
If you need to find initial velocity (u): u = v - at
General Transposition Steps:
Identify the variable you want to isolate.
Perform inverse operations on both sides of the equation to move other terms away from the target variable.
Addition becomes subtraction.
Subtraction becomes addition.
Multiplication becomes division.
Division becomes multiplication.
Simplify the resulting equation.
Algebraic expressions involving multiplication and division of polynomials.
1. Multiplication of Polynomials
Distributive Property: The key to multiplying polynomials is the distributive property. Each term in the first polynomial must be multiplied by each term in the second polynomial.
Combining Like Terms: After distributing, combine any terms with the same variable and exponent.
Examples:
(x + 2)(x + 3)
x(x + 3) + 2(x + 3)
x2 + 3x + 2x + 6
x2 + 5x + 6
(2a - 1)(3a + 4)
2a(3a + 4) - 1(3a + 4)
6a2 + 8a - 3a - 4
6a2 + 5a – 4
(x + 1)(x2 - x + 1)
x(x2 - x + 1) + 1(x2 - x + 1)
x3 - x2 + x + x2 - x + 1
x3 + 1
2. Division of Polynomials
Long Division: Polynomial long division is similar to long division with numbers.
Factoring and Canceling: If possible, factor the polynomials and cancel common factors.
Examples:
(x2 + 5x + 6) / (x + 2)
Using factoring: (x + 2)(x + 3) / (x + 2)
Canceling (x + 2): x + 3
(x3 - 8) / (x - 2)
Using factoring of a difference of cubes: (x - 2)(x2 + 2x + 4) / (x - 2)
Follow Order of Operations: When an expression involves both multiplication and division, perform the operations from left to right.
Simplify as You Go: Simplify each multiplication or division step before moving on to the next one.
Factoring is Key: Often, factoring is crucial for simplifying complex expressions.
Example:
[(x + 1)(x + 2)] / (x + 1)
First, multiply: (x2 + 3x + 2) / (x + 1)
Then, factor: [(x + 1)(x + 2)] / (x + 1)
Then cancel: x + 2
Algebraic expressions with different types of indices (exponents)
1. Whole Number Indices
Definition:
A whole number index indicates how many times a base is multiplied by itself.
Example: x3 = x × x × x
Evaluation:
Simply perform the repeated multiplication.
Example: 24 = 2 × 2 × 2 × 2 = 16
Algebraic expressions:
when evaluating algebraic expressions, you will often be given a value for the variable. Then you will simply substitute that value into the expression, and then perform the calculation.
Example: if the expression is x3, and x=3, then the value of the expression is 33= 27.
2. Fractional Indices
Definition:
A fractional index represents a root and a power.
The denominator of the fraction indicates the root.
The numerator indicates the power.
Example: xm/n = (n√x)m
Evaluation:
Take the nth root of the base.
Raise the result to the mth power.
Example: 82/3 = (3√8)2 = 22 = 4
Key Points:
x1/2 is the square root of x.
x1/3 is the cube root of x.
3. Decimal Indices
Definition:
Decimal indices can be converted to fractional indices, or evaluated using a calculator.
Evaluation:
Conversion to Fractions: If the decimal terminates or repeats, convert it to a fraction and then evaluate as a fractional index.
Example: x0.5 = x1/2 = √x
Calculator Use: For non-terminating, non-repeating decimals, use a calculator with an exponent function (often denoted as "xy" or "^").
Example: 51.7 ≈ 16.19
Important Considerations:
When working with decimal indices, especially irrational ones, the results are often approximations.
Examples of Evaluating Algebraic Expressions:
Whole Number Index:
Evaluate x3 when x = 4.
Solution: 43 = 4 × 4 × 4 = 64
Fractional Index:
Evaluate 163/4.
Solution: (4√16)3 = 23 = 8
Decimal Index:
Evaluate 92.5
Solution: 95/2 = (√9)5 = 35 = 243.
Or, using a calculator, 92.5 = 243.
Key Reminders:
Order of Operations: Always follow the order of operations (BODMAS/PEMDAS) when evaluating expressions.
Calculator Accuracy: Be mindful of rounding errors when using calculators with decimal indices.
Fractional index understanding: Make sure to fully understand the relationship between fractional indicies, and roots.
Factorization
1. Factorization by Common Grouping
Step 1: Group terms that have common factors.
Step 2: Factor out the common factor from each group.
Step 3: If there's a common binomial factor, factor it out.
Example: Factor 𝑎𝑥 + 𝑎𝑦 + 𝑏𝑥 + 𝑏𝑦
Group: (𝑎𝑥 + 𝑎𝑦) + (𝑏𝑥 + 𝑏𝑦)
Factor: 𝑎(𝑥 + 𝑦) + 𝑏(𝑥 + 𝑦)
Factor common binomial: (𝑥 + 𝑦)(𝑎 + 𝑏)
Example: Factor 2𝑥𝑦 + 6𝑥 + 3𝑦 + 9
Group: (2𝑥𝑦 + 6𝑥) + (3𝑦 + 9)
Factor: 2𝑥(𝑦 + 3) + 3(𝑦 + 3)
Factor common binomial: (𝑦 + 3)(2𝑥 + 3)
2. Factorization by Difference of Two Squares
Formula: 𝑎2 − 𝑏2 = (𝑎 + 𝑏)(𝑎 – 𝑏)
Step 1: Identify if the expression is in the form 𝑎2 − 𝑏2.
Step 2: Determine 'a' and 'b'.
Step 3: Apply the formula.
Example: Factor 𝑥2 − 25
x² is a², and 25 is 5² (so 5 is b).
Result: (𝑥 + 5)(𝑥 – 5)
Example: Factor 4𝑦2 − 9𝑥2
4𝑦2 is (2𝑦)2, 𝑎𝑛𝑑 9𝑥2 𝑖𝑠 (3𝑥)2
Result: (2𝑦 + 3𝑥)(2𝑦 – 3𝑥)
3. Factorizing Quadratic Expressions
Form: 𝑎𝑥2 + 𝑏𝑥 + 𝑐
Case 1: a = 1 (Simple Quadratic)
Step 1: Find two numbers that multiply to 'c' and add to 'b'.
Step 2: Form two binomials using those numbers.
Example: Factor 𝑥2 + 7𝑥 + 12
Numbers that multiply to 12 and add to 7 are 3 and 4.
Result: (𝑥 + 3)(𝑥 + 4)
Example: Factor 𝑥2 − 2𝑥 − 15
Numbers that multiply to -15 and add to -2 are -5 and 3.
Result: (x - 5)(x + 3)
Case 2: 𝒂 ≠ 𝟏 (More Complex Quadratic)
Step 1: Find two numbers that multiply to 'ac' and add to 'b'.
Step 2: Rewrite the middle term (𝑏𝑥) using those two numbers.
Step 3: Factor by grouping.
Example: Factor 2𝑥2 + 5𝑥 + 2
𝑎𝑐 = 2 × 2 = 4. Numbers that multiply to 4 and add to 5 are 4 and 1.
Rewrite: 2𝑥2 + 4𝑥 + 𝑥 + 2
Factor by grouping: 2𝑥(𝑥 + 2) + 1(𝑥 + 2)
Result: (𝑥 + 2)(2𝑥 + 1)
Example: Factor 3𝑥2 − 10𝑥 + 8
𝑎𝑐 = 3 × 8 = 24. Numbers that multiply to 24 and add to -10 are -6 and -4.
Rewrite: 3𝑥2 − 6𝑥 – 4𝑥 + 8
Factor by grouping: 3𝑥(𝑥 − 2) − 4(𝑥 − 2)
Result: (𝑥 − 2)(3𝑥 − 4)
4. Determining if a Quadratic Expression is a Perfect Square
Form: 𝑎2 ± 2𝑎𝑏 + 𝑏2
Conditions:
The first and last terms must be perfect squares.
The middle term must be twice the product of the square roots of the first and last terms.
Perfect Square Trinomial Formulas:
𝑎2 + 2𝑎𝑏 + 𝑏2 = (𝑎 + 𝑏)2
𝑎2 − 2𝑎𝑏 + 𝑏2 = (𝑎 − 𝑏)2
Example: Is 𝑥2 + 6𝑥 + 9 a perfect square?
x² is a perfect square (x²).
9 is a perfect square (3²).
2 × 𝑥 × 3 = 6𝑥 (which is the middle term).
Therefore, 𝑥2 + 6𝑥 + 9 = (𝑥 + 3)2
Example: Is 4𝑥2 − 12𝑥 + 9 a perfect square?
4𝑥2 is a perfect square (2𝑥)2.
9 is a perfect square (3²).
2 × 2𝑥 × 3 = 12𝑥 (which is the absolute value of the middle term).
Therefore, 4𝑥2 − 12𝑥 + 9 = (2𝑥 – 3)2
Example: Is 𝑥2 + 5𝑥 + 4 a perfect square?
x² is a perfect square. 4 is a perfect square. However, 2 × x × 2 = 4x, which is not 5x. Therefore, this expression is not a perfect square.
Solving Linear Equations with One Unknown
Example: Solve 3𝑥 + 5 = 14
3𝑥 + 5 = 14
3𝑥 + 5 − 5 = 14 − 5
3𝑥 = 9
(3𝑥) / 3 = 9 / 3
𝑥 = 3
Solving Simultaneous Linear Equations (Two Unknowns)
A polynomial expression is a combination of variables (usually 'x'), constants, and exponents, combined using addition, subtraction, and multiplication.
To evaluate a polynomial expression, you substitute a given value for the variable and perform the indicated operations.
Example 1:
Evaluate the polynomial expression 3𝑥2 − 2𝑥 + 5 when 𝑥 = 2.
Substitute 𝑥 = 2: 3(2)2 − 2(2) + 5
Simplify: 3(4) – 4 + 5 = 12 – 4 + 5 = 13
Example 2:
Evaluate the polynomial expression x³ - 4x when x = -1.
Substitute 𝑥 = −1: (−1)3 − 4(−1)
Simplify: −1 + 4 = 3
2. Function Notation
Function notation is a way to represent a relationship between an input (usually 'x') and an output (usually 'y').
It uses the form f(x), where:
'f' is the name of the function.
'x' is the input variable.
'𝑓(𝑥)' represents the output value of the function when the input is 'x'.
Example:
If 𝑦 = 2𝑥 + 1, we can write it in function notation as 𝑓(𝑥) = 2𝑥 + 1.
To find the value of 𝑓(3), we substitute 𝑥 = 3: 𝑓(3) = 2(3) + 1 = 7.
3. Polynomial Functions
A polynomial function is a function that can be expressed in the form:
𝑓(𝑥) = 𝑎n𝑥n + 𝑎n-1𝑥n-1 + … + 𝑎1𝑥 + 𝑎0
Where:
'𝑛' is a non-negative integer (the degree of the polynomial).
The exponents in a polynomial function must be non-negative integers.
Polynomial functions are defined for all real numbers.
Function notation is very useful for working with polynomial functions
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Polynomial Functions
To evaluate a polynomial function, substitute the given input value for 'x' and simplify.
Example:
Given f(x) = x2 - 3x + 2, find f(4).
f(4) = (4)2 - 3(4) + 2
f(4) = 16 - 12 + 2
f(4) = 6
Nesting Method (Horner's Method):
The "nesting" method, also known as Horner's method or synthetic substitution, is a very efficient way to evaluate polynomial expressions, especially for higher-degree polynomials. It minimizes the number of multiplications needed, which can reduce rounding errors and improve computational speed.
How the Nesting Method Works
Consider a polynomial:
p(x) = anxn + an-1xn-1 + ... + a1x + a0
To evaluate p(c) using the nesting method, you rewrite the polynomial as:
Efficiency: It reduces the number of multiplications, which can be significant for higher-degree polynomials.
Accuracy: Fewer multiplications help minimize rounding errors.
Simplicity: The process is straightforward and can be easily implemented in computer programs.
Synthetic Division: The nesting method is closely related to synthetic division, which is used to divide polynomials.
The Remainder Theorem
Statement: It helps you find the remainder when you divide a polynomial by a linear expression (like x - a) without doing long division.
If a polynomial p(x) is divided by (x – c), then the remainder is p(c).
Application:
It allows you to find the remainder of a polynomial division without actually performing the long division.
You simply substitute the value 'c' into the polynomial.
Example 1:
Find the remainder when p(x) = x3 - 4x2 + 5x + 3 is divided by (x – 2).
According to the Remainder Theorem, the remainder is p(2).
Try x = 1: p(1) = 1 – 2 – 5 + 6 = 0. So, (x – 1) is a factor.
Using polynomial division or synthetic division, divide p(x) by (x – 1) to get x2 - x – 6.
Factor x2 - x – 6: (x – 3)(x + 2).
Therefore, p(x) = (x – 1)(x – 3)(x + 2).
Factorizing Cubic and Quadratic Expressions
Quadratic Expressions (ax2 + bx + c)
Step 1: Find two numbers: Find two numbers that multiply to 'c' and add to 'b'.
Step 2: Write as factors: Write the expression as two binomials using those numbers.
Example: Factor x2 + 5x + 6
Numbers that multiply to 6 and add to 5 are 2 and 3.
So, x2 + 5x + 6 = (x + 2)(x + 3).
Cubic Expressions (ax3 + bx2 + cx + d)
Step 1: Find a factor using the Factor Theorem: Try plugging in small integers (like 1, -1, 2, -2) into the polynomial until you get 0. This gives you a linear factor (x − a).
Step 2: Divide: Divide the cubic polynomial by the linear factor you found. This will give you a quadratic expression.
Step 3: Factor the quadratic: Factor the quadratic expression.
Step 4: Write all factors: Write the cubic expression as the product of the linear factor and the two factors of the quadratic.
Example: Factor x3 - 6x2 + 11x - 6
Try x = 1: p(1) = 1 – 6 + 11 – 6 = 0. So, (x − 1) is a factor.
Divide x3 - 6x2 + 11x – 6 by (x – 1).
This gives you x2 - 5x + 6.
Factor x2 - 5x + 6: (x – 2)(x – 3).
So, x3 - 6x2 + 11x – 6 = (x – 1)(x – 2)(x – 3).
Indices (exponents)
An index (plural: indices) or exponent indicates how many times a base number is multiplied by itself.
Parts of an Index
Base: The number that is being multiplied by itself. In 53, the base is 5.
Index (Exponent/Power): The number that indicates how many times the base is multiplied by itself. In 53, the index is 3.
Complete expression: 53 is the power, 5 is the base, and 3 is the index.
Rules of Indices (Laws of Exponents)
Here are the fundamental rules of indices:
Rule 1: Multiplication (Same Base)
When multiplying terms with the same base, add the indices.
am × an = am+n
Example: 22 × 23 = 25 = 32
Rule 2: Division (Same Base)
When dividing terms with the same base, subtract the indices.
am ÷ an = am-n
Example: 35 ÷ 32 = 33 = 27
Rule 3: Power of a Power
When raising a power to another power, multiply the indices.
(am)n = amn
Example: (42)3 = 46 = 4096
Rule 4: Zero Index
Any non-zero number raised to the power of zero is equal to 1.
a0 = 1 (where a ≠ 0)
Example: 70 = 1
Rule 5: Negative Index
A negative index indicates a reciprocal.
a-n = 1 / an
Example: 2-3 = 1 / 23 = 1/8
Rule 6: Fractional Index
A fractional index represents a root.
a1/n = n√a (the nth root of a)
am/n = (n√a)m or n√(am)
Example: 81/3 = 3√8 = 2
Example: 43/2 = (√4)3 = 23 = 8
Rule 7: Power of a Product
When a product is raised to a power, each factor is raised to that power.
(ab)n = anbn
Example: (2x)3 = 23x3 = 8x3
Rule 8: Power of a Quotient
When a quotient is raised to a power, both the numerator and denominator are raised to that power.
(a / b)n = an / bn
Example: (3 / 4)2 = 32 / 42 = 9 / 16
Applying Rules of Indices to Simplify Expressions
Example 1: Simplify (x3y2) × (x4y5)
Apply Rule 1 (multiplication): x3+4y2+5
Simplify: x7y7
Example 2: Simplify (12a5b3) / (4a2b)
Apply Rule 2 (division): (12 / 4)a5-2b3-1
Simplify: 3a3b2
Example 3: Simplify (3x2)4
Apply Rule 3 (power of a power) and Rule 7 (power of a product): 34(x2)4
Apply Rule 2 (division) and Rule 5 (negative index): 2x3-(-2)y-1-2
Simplify: 2x5y-3 or 2x5 / y3
Expressing Numbers in Standard Form (Scientific Notation)
Definition: Standard form is a way to express very large or very small numbers using powers of 10.
Form: a × 10n, where:
1 ≤ |a| < 10 (a is a number between 1 and 10, including 1)
n is an integer (positive or negative)
Steps:
Move the decimal point until there is only one non-zero digit to the left of it.
Count how many places you moved the decimal point.
If you moved the decimal to the left, n is positive. If you moved it to the right, n is negative.
Example 1: Large Number
Express 5,400,000 in standard form.
Move the decimal point 6 places to the left: 5.4
n = 6 (moved left)
Standard form: 5.4 × 106
Example 2: Small Number
Express 0.00037 in standard form.
Move the decimal point 4 places to the right: 3.7
n = -4 (moved right)
Standard form: 3.7 × 10-4
Example 3:
Express 234.567 in standard form.
Move the decimal point 2 places to the left: 2.34567
n = 2
Standard form: 2.34567 × 102
Example 4:
Express 0.0987 in standard form.
Move the decimal point 2 places to the right: 9.87
n = -2
Standard form: 9.87 × 10-2
Evaluating Expressions in Standard Form
When you have expressions involving numbers in standard form, you apply the rules of indices and arithmetic operations.
Multiplication: (a × 10n) × (b × 10m) = (a × b) × 10n+m
Division: (a × 10n) / (b × 10m) = (a / b) × 10n-m
Addition/Subtraction: You can only add or subtract numbers in standard form if they have the same power of 10. If they don't, adjust one of the numbers.
(a × 10n) ± (b × 10n) = (a ± b) × 10n
Evaluating Expressions in "Preferred" Standard Form
"Preferred" standard form usually refers to expressing a number in standard form where:
1 ≤ |a| < 10 (as in standard form)
The 'a' value is rounded to a specified number of significant figures or decimal places.
Why "Preferred" Standard Form Matters:
Precision: In science and engineering, the number of significant figures indicates the precision of a measurement. "Preferred" standard form ensures that the result reflects the appropriate level of precision.
Clarity: It makes it easier to compare and interpret very large or small numbers.
Examples:
Example 1:
Calculate (3.14159 × 106) × (2.71828 × 10-3).
(3.14159 × 2.71828) × 106-3 ≈ 8.53973 × 103
If we want the result to 3 significant figures, we would write 8.54 × 103.
In essence, you're converting the logarithmic form back to exponential form.
Examples:
Convert 𝒍𝒐𝒈₁₀(𝟏𝟎𝟎𝟎) = 𝟑 to anti-logarithm:
1000 = 103
Convert 𝒍𝒐𝒈₂(𝟏𝟔) = 𝟒 to anti-logarithm:
16 = 24
Convert 𝒍𝒐𝒈₃(𝟖𝟏) = 𝟒 to anti-logarithm:
81 = 34
Convert 𝒍𝒐𝒈ₑ(𝒙) = 𝟐 to anti-logarithm:
x = e2. e is approximately 2.71828.
Converting Logarithm Bases
Change of Base Formula:
logb(a) = logc(a) / logc(b)
Where:
b is the original base.
a is the argument.
c is the new base.
Example:
Convert log₂(8) to base 10.
log₂(8) = log₁₀(8) / log₁₀(2)
Using a calculator: log₁₀(8) ≈ 0.9031, log₁₀(2) ≈ 0.3010
log₂(8) ≈ 0.9031 / 0.3010 ≈ 3
Converting Numbers to Natural (Napierian) Logarithms
Natural Logarithms:
Natural logarithms use the base 'e' (Euler's number), which is approximately 2.71828.
They are denoted as ln(x) or logₑ(x).
Conversion:
Use a calculator with an 'ln' function.
Example: Find 𝒍𝒏(𝟔𝟒)
Using a calculator, ln(64) ≈ 4.1589.
Applying Logarithm Rules to Solve Indicial Equations
Indicial Equations:
Equations where the variable is in the exponent.
Steps:
Take the logarithm of both sides of the equation.
Apply the power rule of logarithms to bring the exponent down.
Solve for the variable.
Example 1: Solve 2ˣ = 16
Take the logarithm (base 10 or natural logarithm) of both sides: log(2x) = log(16)
Apply the power rule: x × log(2) = log(16)
Solve for x: x = log(16) / log(2)
Using a calculator: x ≈ 1.2041 / 0.3010 ≈ 4
(Check: 24 = 16)
Example 2: Solve 32x – 1 = 81
Take the logarithm of both sides: log(32x – 1) = log(81)
Apply the power rule: (2x − 1) × log(3) = log(81)
Solve for 2x − 1: 2x − 1 = log(81) / log(3)
Using a calculator: 2x − 1 ≈ 4
Solve for x: 2x = 5, x = 5/2 or 2.5
(Check: 32×2.5 - 1 = 34 = 81)
Example 3: Solve 5ˣ = 20
log(5x) = log(20)
x × log(5) = log(20)
x = log(20) / log(5)
x = 1.8614
Example 4: Solve e2x = 10
ln(e2x) = ln(10)
2x × ln(e) = ln(10)
2x × 1 = ln(10)
2x = ln(10)
x = ln(10) / 2
x = 1.1513
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Area
a) Areas of Circles
Formula: Area (𝐴) = 𝜋𝑟2 (where ′𝑟′ is the radius)
Example:
Find the area of a circle with a radius of 5 cm.
𝐴 = 𝜋(5 𝑐𝑚)2 = 25𝜋 𝑐𝑚2 ≈ 78.54 𝑐𝑚2
b) Annulus (Ring)
Definition: An annulus is the region between two concentric circles (circles with the same center).
Formula: Area (𝐴) = 𝜋(𝑅2 − 𝑟2) (where '𝑅' is the outer radius and '𝑟' is the inner radius)
Example:
Find the area of an annulus with an outer radius of 8 cm and an inner radius of 3 cm.
𝐴 = 𝜋(82 − 32) = 𝜋(64 − 9) = 55𝜋 𝑐𝑚2 ≈ 172.79 𝑐𝑚2
c) Cone
Formula: Area of the base = 𝜋𝑟2, Curved surface area = 𝜋𝑟𝑙, Total surface area = 𝜋𝑟(𝑟 + 𝑙). Where r is the radius of the base, and l is the slant height.
Example:
Find the total surface area of a cone with a radius of 4 cm and a slant height of 7 cm.
Gear Ratio: Number of teeth on driven gear / Number of teeth on driving gear.
Timing Belt Ratio: Number of teeth on driven pulley / Number of teeth on driving pulley.
Example:
Crankshaft gear has 20 teeth, Camshaft gear has 40 teeth.
Gear Ratio = 40 / 20
6. Air-Fuel Ratio (AFR)
Definition: The ratio of the mass of air to the mass of fuel in an air-fuel mixture.
Calculation: Measured by sensors or calculated.
Example:
If an engine uses 14.7 kg of air for every 1 kg of fuel, the AFR is 14.7:1.
7. Gear Ratios (Manual Gearbox and Final Drive)
Gear Ratio: Number of teeth on driven gear / Number of teeth on driving gear.
Final Drive Ratio: Number of teeth on ring gear / Number of teeth on pinion gear.
Total Gear Ratio: 𝐺𝑒𝑎𝑟𝑏𝑜𝑥 𝑔𝑒𝑎𝑟 𝑟𝑎𝑡𝑖𝑜 × 𝐹𝑖𝑛𝑎𝑙 𝑑𝑟𝑖𝑣𝑒 𝑟𝑎𝑡𝑖𝑜.
Example:
Gearbox 1st gear ratio = 3.5:1, Final drive ratio = 4:1
Total 1st gear ratio = 3.5 × 4 = 14:1
8. Belt Drive Ratios in Relation to Gear Ratios
Belt Drive Ratio: Diameter of driven pulley / Diameter of driving pulley.
Relationship: Belt drive ratios can be used in combination with gear ratios to achieve desired speed and torque changes.
Example:
If an accessory drive uses a belt with a 2:1 ratio, and the accessory itself has a gear ratio of 3:1, the overall ratio is 2 × 3 = 6:1.
If a gear box has a first gear ratio of 3:1 and the power then goes through a belt drive with a ratio of 1.5:1, then the total ratio is 3 × 1.5 = 4.5:1.
Types of angles and triangles
1. Types of Angles
Acute Angle: An angle measuring less than 90°.
Right Angle: An angle measuring exactly 90°.
Obtuse Angle: An angle measuring greater than 90° but less than 180°.
Straight Angle: An angle measuring exactly 180°.
Reflex Angle: An angle measuring greater than 180° but less than 360°.
Full Rotation (or Full Angle): An angle measuring 360 degrees.
2. Describing and Identifying Different Angles
Adjacent Angles: Angles that share a common vertex and a common side.
Complementary Angles: Two angles whose sum is 90°.
Supplementary Angles: Two angles whose sum is 180°.
Vertical Angles: Two opposite angles formed by intersecting lines. They are equal in measure.
Definition of a Triangle
A triangle is a polygon with three sides and three angles.
Types of Triangles
Acute-Angled Triangle: A triangle in which all three angles are acute (less than 90°).
Right-Angled Triangle: A triangle with one right angle (exactly 90°).
Obtuse-Angled Triangle: A triangle with one obtuse angle (greater than 90°).
Equilateral Triangle: A triangle with all three sides equal and all three angles equal (each 60°).
Isosceles Triangle: A triangle with two sides equal and two angles equal.
Ignition Timing (Spark Ignition Engines)
Concept: Ignition timing is the moment at which the spark plug fires, igniting the air-fuel mixture in the cylinder.
Angular Measurements: Ignition timing is expressed in degrees of crankshaft rotation, typically before top dead center (BTDC).
Calculations:
The ignition timing is specified by the engine manufacturer.
Adjustments are made based on engine load, speed, and other factors (centrifugal and vacuum advance).
Example: Ignition timing of 10° BTDC means the spark plug fires when the crankshaft is 10 degrees before the piston reaches TDC.
Example:
If the engine is under heavy load, the ignition timing may be retarded (reduced) to prevent engine knock.
If the engine is idling, the ignition timing may be advanced to provide a smoother idle.
Piston Travel
What it is: Piston travel is the distance the piston moves within the cylinder from top dead center (TDC) to any given point in its stroke.
How to Calculate:
Piston travel is related to crank angle, connecting rod length, and crank radius.
Crank radius (r) = 40 mm, Connecting rod length (l) = 160 mm, Angle of obliquity (φ) = 12.5°.
sin𝜃 = (160/40) sin12.5°
𝑠𝑖𝑛 𝜃 = 4 × 0.2164
𝑠𝑖𝑛 𝜃 = 0.8656
𝜃 = 𝑎𝑟𝑐𝑠𝑖𝑛(0.8656) ≈ 60°
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Coordinate Geometry and Calculus Concepts
1. Calculating the Midpoint of a Straight Line
Midpoint Formula:
The midpoint of a line segment between two points (x1, y1) and (x2, y2) is found using the formula:
𝑀𝑖𝑑𝑝𝑜𝑖𝑛𝑡 = (x1 + x2)2, (y1 + y2)2
Steps:
Identify the coordinates: Determine the coordinates of the two endpoints of the line segment.
Apply the formula: Substitute the coordinates into the midpoint formula.
Calculate: Perform the calculations to find the coordinates of the midpoint.
Example:
Find the midpoint of the line segment between points A (2, 5) and B (6, 1).
𝑀𝑖𝑑𝑝𝑜𝑖𝑛𝑡 = (2 + 6)2
𝑀𝑖𝑑𝑝𝑜𝑖𝑛𝑡 = (8)2, (5 + 1)2
𝑀𝑖𝑑𝑝𝑜𝑖𝑛𝑡 = (4, 3)
2. Calculating the Slope or Gradient of a Straight Line
Slope Formula:
The slope (m) of a line passing through two points (x1, y1) and (x2, y2) is calculated using the formula:
𝑚 = (y2 − y1) / (x2 − x1)
Steps:
Identify the coordinates: Determine the coordinates of two distinct points on the line.
Apply the formula: Substitute the coordinates into the slope formula.
Calculate: Perform the calculations to find the slope.
Example:
Find the slope of the line passing through points C (1, 3) and D (4, 9).
𝑚 = (9 − 3) / (4 − 1)
𝑚 = 6 / 3
𝑚 = 2
3. Finding the Equation of a Tangent of a Curve at a Point
Concept:
A tangent line touches a curve at a single point and has the same slope as the curve at that point.
Differentiation is used to find the slope of the curve (the derivative).
Steps:
Find the derivative: Differentiate the equation of the curve to find the derivative, dy/dx (or f′(x)).
Evaluate the derivative: Substitute the x-coordinate of the given point into the derivative to find the slope of the tangent at that point.
Use the point-slope form: Use the point-slope form of a line equation (y − y1 = m(x − x1)) to find the equation of the tangent, where (x1, y1) is the given point and m is the slope.
Simplify: Rearrange the equation into slope-intercept form (y = mx + b) or standard form (Ax + By = C).
Example:
Find the equation of the tangent to the curve y = x² at the point (2, 4).
Find the derivative:
dy/dx = 2x
Evaluate the derivative:
At x = 2, dy/dx = 2(2) = 4 (this is the slope, m)
Use the point-slope form:
y − 4 = 4(x − 2)
Simplify:
y − 4 = 4x − 8
y = 4x − 4
Sketching Straight Line Graphs
Slope-Intercept Form (y = mx + b):
Identify the y-intercept (b): This is the point where the line crosses the y-axis (when x = 0).
Plot the y-intercept: Mark this point on your graph.
Use the slope (m): The slope is "rise over run." From the y-intercept, move up (or down) for the "rise" and right (or left) for the "run" to find another point on the line.
Draw the line: Connect the two points with a straight line.
Example:
Sketch the graph of y = 2x − 1
y-intercept (b) = -1
Slope (m) = 2 (rise = 2, run = 1)
Plot the point (0, -1).
From (0, -1), move up 2 units and right 1 unit to get the point (1, 1).
Draw a line through (0, -1) and (1, 1).
Sketching Quadratic Graphs (Use of Maxima and Minima)
Standard Form (y = ax² + bx + c):
Find the vertex:
The x-coordinate of the vertex is -b / 2a.
Substitute this x-value into the equation to find the y-coordinate of the vertex.
Determine the direction:
If 'a' is positive, the parabola opens upward (minimum point).
If 'a' is negative, the parabola opens downward (maximum point).
Find the y-intercept: Set x = 0 in the equation to find the y-intercept.
Find x-intercepts (if any): Solve the quadratic equation (ax² + bx + c = 0) to find the x-intercepts.
Plot the points: Plot the vertex, y-intercept, and x-intercepts.
Sketch the curve: Draw a smooth, symmetrical curve through the points.
Example:
Sketch the graph of y = x² − 4x + 3
Vertex:
x = −(−4) / 2(1) = 2
y = 2² − 4(2) + 3 = −1
Vertex = (2, −1)
Direction: 'a' = 1 (positive), so the parabola opens upward (minimum).
y-intercept: y = 0² − 4(0) + 3 = 3
x-intercepts:
(x − 3)(x − 1) = 0
x = 3 and x = 1
Plot the points (2, -1), (0, 3), (3, 0), and (1, 0).
Draw a smooth curve through the points.
Sketching Straight Line Graphs
Concept:
A straight line graph represents a linear equation, typically in the form y = mx + c, where 'm' is the slope and 'c' is the y-intercept.
Steps:
Find the y-intercept (c): This is the point where the line crosses the y axis (when x = 0). Plot this point.
Use the slope (m): The slope tells you how much the y-value changes for every unit change in the x-value. If m is positive, the line goes upward; if negative, downward.
If m = 2, for example, go up 2 units on the y-axis for every 1 unit you move right on the x-axis.
Plot a second point: Use the slope to find another point on the line.
Draw the line: Connect the two points with a straight line.
Sketching Quadratic Graphs (Use of Maxima and Minima)
Concept:
A quadratic graph represents a quadratic equation, typically in the form y = ax² + bx + c. The graph is a parabola.
Maxima and minima are the highest and lowest points of the parabola, respectively.
Steps:
Find the vertex (maxima or minima):
The x-coordinate of the vertex is given by -b / 2a.
Substitute this x-value back into the equation to find the y coordinate of the vertex.
Determine the direction:
If 'a' is positive, the parabola opens upward (minimum point).
If 'a' is negative, the parabola opens downward (maximum point).
Find the y-intercept: Set x = 0 in the equation to find the y-intercept.
Find the x-intercepts (if any): Solve the quadratic equation ax² + bx + c = 0 to find the x-intercepts.
Plot the points: Plot the vertex, y-intercept, and x-intercepts.
Sketch the curve: Draw a smooth, symmetrical curve through the points.
Explanation of Illustrations:
Straight Line:
The line is shown with a positive slope.
The point where it crosses the y-axis would be the y intercept.
The line continues infinitely in both directions.
Quadratic Graph:
The graph shows a parabola opening upward (minimum point).
The vertex is the lowest point.
The curve is symmetrical around a vertical line that passes through the vertex.
Differentiation
Determining the Slope of a Curve Algebraically
Concept:
Differentiation allows us to find the instantaneous rate of change of a function, which represents the slope of the tangent line to the curve at any given point.
The derivative of a function f(x), denoted as f'(x) or dy/dx, gives the slope of the curve at any x-value.
Process:
Find the derivative: Use differentiation rules to find the derivative of the function.
Evaluate at a point: Substitute the x-coordinate of the point where you want to find the slope into the derivative.
Example:
Find the slope of the curve y = x² at the point x = 3.
Find the derivative: dy/dx = 2x
Evaluate: At x = 3, dy/dx = 2(3) = 6.
Therefore, the slope of the curve at x = 3 is 6.
Differentiating Coefficients of Powers of x and Polynomials Only
Power Rule:
If y = xⁿ, then dy/dx = nxⁿ⁻¹
If y = axⁿ, then dy/dx = an xⁿ⁻¹ (where 'a' is a constant)
Constant Rule:
If y = c (a constant), then dy/dx = 0
Sum/Difference Rule:
If y = u(x) ± v(x), then dy/dx = u'(x) ± v'(x)
Polynomials:
A polynomial is a function of the form f(x) = a0 + a1x + a2x² + … + anxⁿ
To differentiate a polynomial, differentiate each term separately using the power and constant rules.
Examples:
y = x³: dy/dx = 3x²
y = 5x⁴: dy/dx = 20x³
y = 7: dy/dx = 0
y = 2x³ + 4x² - 6x + 1: dy/dx = 6x² + 8x - 6
Determining Velocity and Acceleration Through Differentiation
Position, Velocity, and Acceleration:
If s(t) represents the position of an object at time t, then:
Velocity (v(t)) is the rate of change of position with respect to time: v(t) = ds/dt.
Acceleration (a(t)) is the rate of change of velocity with respect to time: a(t) = dv/dt = d²s/dt².
Steps:
Find the velocity: Differentiate the position function s(t) to find the velocity function v(t).
Find the acceleration: Differentiate the velocity function v(t) to find the acceleration function a(t).
Evaluate at a time: Substitute the given time (t) into the velocity and acceleration functions to find the velocity and acceleration at that time.
Example:
The position of an object is given by s(t) = t³ - 6t² + 9t. Find the velocity and acceleration at t = 2.
Velocity: v(t) = ds/dt = 3t² - 12t + 9
Acceleration: a(t) = dv/dt = 6t - 12
Evaluate:
At t = 2, v(2) = 3(2)² - 12(2) + 9 = -3
At t = 2, a(2) = 6(2) - 12 = 0
Thus, at t=2, the velocity is -3, and the acceleration is 0.
Integration
Determining Indefinite Integrals of Polynomials
Concept:
Integration is the reverse process of differentiation.
An indefinite integral represents a family of functions whose derivative is the given function.
For a polynomial, we use the power rule of integration.
Power Rule of Integration:
If f(x) = xⁿ, then ∫f(x)dx = (xⁿ⁺¹)/(n + 1) + C (where n ≠ -1 and C is the constant of integration).
If f(x) = axⁿ, then ∫f(x)dx = a(xⁿ⁺¹)/(n + 1) + C
Constant Rule of Integration:
If f(x) = c (a constant), then ∫f(x)dx = cx + C.
Sum/Difference Rule of Integration:
∫[u(x)± v(x)]dx = ∫u(x)dx ± ∫v(x)dx
Polynomials:
Integrate each term of the polynomial separately using the power and constant rules.
Examples:
∫x²dx = (x³)/3 + C
∫4x³dx = 4(x⁴)/4 + C = x⁴ + C
∫5dx = 5x + C
∫(3x² + 2x - 1)dx = (3x³)/3 + (2x²)/2 - x + C
Determining the Constant (C) of Integration
Concept:
When finding an indefinite integral, we always add a constant of integration (C) because the derivative of a constant is zero.
To determine the specific value of C, we need additional information, usually a given point on the function (an initial condition).
Steps:
Find the indefinite integral: Integrate the given function.
Use the given point: Substitute the x and y coordinates of the given point into the indefinite integral.
Solve for C: Solve the resulting equation for C.
Example:
Find the integral of f(x) = 2x, given that the function passes through the point (1, 5).
Find Indefinite integral: ∫2xdx = x² + C
Use the given point: Substitute x = 1 and y = 5 into the integral: 5 = 1² + C
Solve for C: 5 = 1 + C → C = 4
Therefore, the specific integral is y = x² + 4.
Another Example:
Find the integral of f(x) = 3x² + 2x given that the function passes through the point (2,10).
Boldface Letters: A common notation is to use boldface letters (e.g., v, F, a).
Arrow Over the Letter: Another common notation is to place an arrow over the letter (e.g., →v, →F).
Component Form: Vectors can be represented in component form, especially in a coordinate system.
In a 2D plane: v = (vx, vy) or v = vxi + vyj
In 3D space: v = (vx, vy, vz) or v = vxi + vyj + vzk
Magnitude Notation: The magnitude of a vector v is denoted by |v| or ||v||.
Unit Vector Notation: A unit vector, which has a magnitude of 1, is often denoted with a "hat" over the letter. For example, a unit vector in the direction of vector v is notated as â.
Types of Vectors
Zero Vector: A vector with a magnitude of zero. It has no specific direction. Notation: 0
Unit Vector: A vector with a magnitude of 1. Used to indicate direction. Notation: Often denoted with a "hat" (e.g., â).
Position Vector: A vector that specifies the position of a point relative to an origin. Starts at the origin and ends at the point.
Displacement Vector: A vector representing the change in position of an object. Starts at the initial position and ends at the final position.
Velocity Vector: A vector that represents the rate of change of an object's position with respect to time, including its direction.
Force Vector: A vector representing a push or pull on an object, including its direction.
Equal Vectors: Vectors that have the same magnitude and direction.
Negative Vectors: Vectors that have the same magnitude but opposite directions.
Vector Addition (Without Proofs)
Concept: Vector addition combines two or more vectors to produce a resultant vector.
Method 1: Component-wise Addition
Break Vectors into Components: Express each vector in its component form (e.g., in 2D, v = (vx, vy)).
Add Corresponding Components: Add the x-components together and the y-components together.
Resultant Vector: The sums of the components form the components of the resultant vector.
Example (2D):
Vector A = (3, 4)
Vector B = (1, -2)
Resultant Vector (A + B) = (3 + 1, 4 + (-2)) = (4, 2)
Method 2: Graphical (Head-to-Tail) Method
Draw the First Vector: Draw the first vector as an arrow.
Draw the Second Vector: Place the tail of the second vector at the head of the first vector.
Draw the Resultant Vector: Draw an arrow from the tail of the first vector to the head of the second vector. This arrow represents the resultant vector.
Important Notes:
Vector addition is commutative (A + B = B + A).
Vector addition is associative (A + (B + C) = (A + B) + C).
When using the component method, the vectors must have the same number of dimensions.
Component Method Examples
Example 1: 2D Vectors
Vector A = (5, 2)
Vector B = (-3, 6)
A + B = (5 + (-3), 2 + 6) = (2, 8)
Example 2: 3D Vectors
Vector C = (1, -4, 3)
Vector D = (2, 0, -1)
C + D = (1 + 2, -4 + 0, 3 + (-1)) = (3, -4, 2)
Example 3: Adding Multiple Vectors
Vector E = (2, -1)
Vector F = (0, 3)
Vector G = (-4, -2)
E + F + G = (2 + 0 + (-4), -1 + 3 + (-2)) = (-2, 0)
Graphical Method Examples (Conceptual)
Example 1: Two Vectors in 2D
Imagine Vector A as an arrow pointing northeast.
Imagine Vector B as an arrow pointing southeast.
Place the tail of Vector B at the head (tip) of Vector A.
Draw a new arrow from the tail of Vector A to the head of Vector B. This new arrow is the resultant vector (A + B).
Example 2: Vectors with Opposite Directions
Imagine Vector C as an arrow pointing directly right.
Imagine Vector D as an arrow pointing directly left (but shorter than C).
Place the tail of Vector D at the head of Vector C.
Draw an arrow from the tail of Vector C to the head of Vector D. The resultant vector (C + D) will be an arrow pointing right, but shorter than Vector C.
Example 3: Vectors at Right Angles
Imagine Vector E as an arrow pointing directly up.
Imagine Vector F as an arrow pointing directly right.
Place the tail of Vector F at the head of Vector E.
Draw an arrow from the tail of Vector E to the head of Vector F. The resultant vector (E + F) will be an arrow pointing diagonally up and to the right.