Quadratic
Equations
Graphing
Y-Intercept(s)
Multiply (a)(x)(r)
Parabola opening
Downwards
a<0
Upwards
a>0
X-Intercept(s)
Formula: f(x)=a(x-r)(x-r)
Intercepts are: (r,s)
"A" value
The value of "a" in the formula
Formula: (r+s/2)
Equations
ax^2+bx+c = 0
Factored Forms
Used to find the Roots
f(x) = a(x-r )(x-r )
Quadratic Formula
Used to solve a quadratic equation
(-b±√b^2-4ac) / 2a
Vertex Form
Used to find the Vertex
Vertex
y = a(x – h)^2 + k
Standard Form
To find the X-Intercept
y=ax^2+bx+c
Definitions
Factor
Splitting an expression
into multiple expressions
Which finds whether there are
two solutions, one solution, or no solutions
Vertex
The point which connects
both sides of the parabola
Y-Intercept
The point where the parabola
crosses the y-axis
X-Intercept
Roots
Zeroes
The point where the parabola
crosses the x-axis
Axis of Symmetry
splits the parabola into two equal parts
Solving an Equation
Solve Using the Quadratic Formula
Solve by Graphing
Graph 2 equations on the same axes,
then find the Point of Intersection
Finding the Point of Intersection
1) solve for x
2) plug the value of x into the
original equation to find y
Solve by Factoring
Simplify the equation
Example: x^2-6x+8=0
(x-___)(x-____)=0
(x-4)(x-2)=0
Zero Product Property
When equation has product of two simple
equations, one of the two (or both) must be equal to zero
1) Factor
2) Find the 2 Solutions
3) Solve each Equation
Example: (x-4)(x-2)
(x-4)=0 because x=4 and/or
(x-2)=0 because x=2
Problem Solving
Communications
concluding statement
let statement for variables
Solving
solve using factoring or quadratic formula
Interpretation
Discriminant
b^2-4ac<0
Two Real and Different Roots (3)
b^2-4ac=0
One Real and Equal Root (1)
b^2-4ac>0
No Real Roots (0)