Answer:
Vertex form is y = (2x+2)^2 + 7
Step-by-step explanation:
The vertex form is
y = (x-h)^2+k
Where (h,k) is the vertex.
Let
y = 4x^2 + 8x +15
Add -15 on both sides
y-15 = 4x^2+8x+15 -15
y-15 = 4x^2+8x
Making whole square formula on Right hand side (a+b)^2
(2x)^2 + 2(2x)(2)+(2)^2 = (2x+2)^2
Adding (2)^2 on both sides of the equation
y-15+(2)^2=4x^2+8x+(2)^2
y-15+4=(2x+2)^2
y-7 = (2x+2)^2
y = (2x+2)^2 + 7
So, Vertex form is y = (2x+2)^2 + 7
