Question

\[f(x)=8x ^{2}+16x-3\]
vertex?

Answer 1

put it in vertex form
f(x)=a(x-h)^2+k

Answer 2

f(x)=8(x^2+2x)-3
f(x)=8(x^2+2x+1)-3-8
f(x)=8(x+1)^2-11

Answer 3

is that what you got when you tried it?