Algebra 2 - Chapter 4 Review

Questions and Answers

Which of the following are steps to factoring? (Select all that apply)

Factor out GCF if possible (correct)

Factor by grouping (correct)

Use the quadratic formula

Rewrite in standard form if necessary (correct)

What is the equation to find the vertex for the equation y=ax^2+bx+c?

x = -b/2a

How do you solve the equation 8x^2=40 by square roots?

x = rad 5

What does a complex number look like in standard form?

a + bi Signup and view all the answers

What is the conjugate of the complex number 3-4i?

3 + 4i Signup and view all the answers

What is the additive inverse of the complex number a + bi?

-a - bi Signup and view all the answers

Match the following operations with their results:

Addition of (4+2i) and (-6-7i) = -2 - 5i Subtraction of (5-2i) and (-2-3i) = 7 + i Signup and view all the answers

To write a quadratic function in standard form with zeros -4 and 7, you need to multiply the expressions (x + )(x - ).

4, 7 Signup and view all the answers

To evaluate two complex numbers, real parts are added and imaginary parts are added.

True Signup and view all the answers

Study Notes

Factoring Steps

Rewrite the expression in standard form if necessary.
Factor out the Greatest Common Factor (GCF) if possible.
Utilize "magic numbers" for identifying factors.
Apply factor by grouping for polynomials with four terms.
Set variable to zero when factoring, e.g., for (2a = 0), (a = 0).

Solving by Graphing

Identify the x-intercepts of the equation (y = ax^2 + bx + c).
Find the vertex using the formula (x = -\frac{b}{2a}).
Example: For (y = x^2 - 6x + 8), calculate (x = \frac{6}{2(1)} = 3).
Always make a table for at least five values when graphing.

Solving by Square Roots

Rearrange the equation to the form (x^2 = y).
Solve by taking the square root of both sides, remembering to include the plus/minus sign.
Example: From (8x^2 = 40) to (x^2 = 5) leads to (x = \sqrt{5}).

Factoring Techniques

For a binomial, check for the difference of squares.
For a trinomial, verify if it’s a perfect square trinomial and use magic numbers.
For expressions with four terms, apply factor by grouping.

Writing Quadratic Functions

To write a quadratic function from zeros, such as -4 and 7:
- Set each zero to zero: (x + 4 = 0) and (x - 7 = 0).
- Multiply the expressions: ((x + 4)(x - 7) = x^2 - 3x - 28).

Complex Numbers

Imaginary unit (i) represents (\sqrt{-1}), making (i^2 = -1).
Use (i) to express the square roots of negative numbers.

Standard Form of Complex Numbers

The standard form of a complex number is expressed as (a + bi).
Example: (3 + 7i) where (3) is the real part and (7i) is the imaginary part.

Evaluating Complex Numbers

For equations like (4x + 10i = 2 - (4y)i):
- Equate real parts: (4x = 2) leading to (x = \frac{1}{2}).
- Equate imaginary parts: (10 = -4y), resulting in (y = -\frac{5}{2}).

Conjugates of Complex Numbers

The conjugate of (a + bi) is (a - bi).
Example: The conjugate of (3 - 4i) is (3 + 4i).
The real part remains unchanged while the imaginary part changes sign.

Additive Inverse of Complex Numbers

The additive inverse of (a + bi) is (-a - bi).
Involves changing the signs for both the real and imaginary components.

Adding and Subtracting Complex Numbers

Addition Example:
- ((4 + 2i) + (-6 - 7i)):
  - Real: (4 - 6 = -2)
  - Imaginary: (2i - 7i = -5i)
  - Solution: (-2 - 5i)
Subtraction Example:
- ((5 - 2i) - (-2 - 3i)):
  - Real: (5 + 2 = 7)
  - Imaginary: (-2i + 3i = i)
  - Solution: (7 + i)
Special Caution: Adding additive inverses results in zero.

Description

This quiz covers key concepts from Algebra 2 Chapter 4, focusing on factoring and solving equations by graphing. You will learn to identify the steps involved in factoring and how to find the vertex of a quadratic equation. Enhance your understanding of these essential algebraic techniques.