exam 2 Flashcards
section 10 review
Section 10.1
Explain the process of extracting square roots.
x^2 = 4
- Isolate the squared term.
- Take the square root of each side. (Don’t forget, + and - in front of the constant)
- Simplify the square root.
- Solve by isolating the variable.
Section 10.1
Explain the process of completing the square.
x^2 + 8x + 20 = 0
(When the diamond/ac process doesn’t work)
- Write the equation in form: x^2 + bc = c
- Add the variable from (b/2)^2 to both sides of the equation.
- Extract the square.
- Solve the resulting equation.
Don’t forget the + and - for the square root of the constant (right side
Section 10.1
What is the shortcut method to completing the square?
(With the “b” variable)
You use the “b/2” to extract the square on the left side and add the result variable of “(b/2)^2” to the right side constant.
EX: (x+3)(x+3) = 2 + 9
Section 10.2
What is the quadratic formula?
x = -b + - SQRT b^2 - 4ac / 2a
Section 10.2
What is the condition to using the quadratic formula?
(Think of what the equation must be to equal to.)
The equation must be equal to zero.
Section 10.3
How can we make an equation that is not a quadratic into a quadratic equation?
(Think substitute)
We substitute “u” for a common variable to make it into a quadratic
Section 10.3
When we square both sides of an equation we must always?
Check for extraneous solutions. (Proof/check our solutions)
Section 10.3
When solving Rational Equations we must get rid of solutions that produce (blank) in the denominator.
Zero.
Section 10.4
The graph of quadratic equations are U-Shaped and called (blank).
Parabolas.
Section 10.4
What is the general parent graph of all parabolas?
y = x squared
Section 10.4
What is the standard form of (graph) Quadratic Equations?
y = a^2 + bx + c
Section 10.4
What are the 4 steps to graphing quadratic equations in the standard form?
- Finding the vertex
- Find the y-intercept.
- Find the x-intercepts (if any).
- Use axis of symmetry to add any additional points to graph.
Section 10.4
How do you find the vertex?
Use the formula x = -b / 2a to find the x-coordinate of the vertex.
Then substitute the x-value in the original equation to find the y-coordinate.
Section 10.4
How do you find the y-intercept?
Replace x with 0.
Section 10.4
How do you find the x-intercepts (if there are any)?
Replace y with 0 and solve for x (when possible).