Question

Please help me!

f(x) = x² + 2x - 15
1. Factor the function into its two binomial factors.
2.
From the factors, show how to find the zeros/x-intercepts.
Calculate the vertex point by first finding the axis of symmetry.
4. Is the vertex point a minimum or maximum? How do you know?
3.

Answer 1

Explanation:

f(x) = x² + 2x - 15

0=x² + 2x - 15

a+b = 2

a*b = -15

0 = (x-5)(x-3)

x+5 = 0

x - 3 = 0

x = -5, 3

vertex = -b/2a

-(2)/2(1)

-2/2

x = -1

(-1)² + 2(-1) - 15

-16

vertex = (-1, -16)

vertex is point of minimum as a is positive.