Question

put y= 4x^2 + 7x in vertex form. ( y= a(x-h)^2 + k
I know that h is -7/8 but I can't find k.

Answer 1

a = 4 since the leading coefficient is 4

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

y= 4(x-(-7/8))^2 + k

y= 4(x+7/8)^2 + k

0= 4(0+7/8)^2 + k ... plug in (0,0) since this point lies on y= 4x^2 + 7x

0 = 4(7/8)^2 + k

0 = 4(49/64) + k

0 = 49/16 + k

keep going to solve for k

Answer 2

So k is -49/16?

Answer 3

yep

Answer 4

thank you!

Answer 5

yw