Y=x^2+2x-15 in vertex form

Question

asked Aug 14, 2020 3.6k views

2 Answers

Tmn · Answer 1 · 2020-08-21T16:03:55+0000

ANSWER

The vertex form is:

$y = {(x + 1)}^(2) - 16$

EXPLANATION

The given function is:

$y = {x}^(2) + 2x - 15$

Add and subtract the square of half the coefficient of x.

$y = {x}^(2) + 2x + ( {1)}^(2) - {(1)}^(2) - 15$

The first three terms for a quadratic trinomial.

$y = {(x + 1)}^(2) - 16$

This is now in the form

y = a(x - h) ^(2) + k

where (h,k)=(-1,-16) is the vertex