What is the vertex form of y= 5x^2 + 5x -12 ?

1 Answer
Mar 5, 2018

vertex = (-1/2, -13.25)

Explanation:

y = 5x^2 + 5x - 12

take 5 as a common factor from the first two terms

y = 5(x^2 + x) - 12

completing square

y = 5(x^2 + x + (1/2)^2) - 12 -5/4

for completing square you take half the coefficient of x and square it
and we subtract 5/4 because from completing square we get 1/4 so 1/4 times 5 is 5/4 because it is positive inside it must be negative then

y = 5(x+1/2)^2 - 13.25

from the law y = (x - h)^2 + k

the vertex is = (-1/2, -13.25)