Warm Up
1. Write the function in vertex form using the completing the square method, then state the vertex.
f(x) = x2 ­ 8x ­ 40
2. Using your vertex form, find the x­intercepts of the graph.
Vertex Form
2
g(x) = a(x ­ h) + k
Vertex:
Standard Form
g(x) = ax2 + bx + c
Factored Form h(x) = k(x ­ r)(x ­ s) Vertex Form f(x) = a(x ­ h)2 + k Completing the Square
x2 + 12x ­ 5
Use the quadratic formula to solve
x2 ­ 6x + 13 = 0
*Discriminant
No real solutions
One real solution
Two real solutions
Complex/Imaginary Numbers
#6