I have tried several times to find the vertex, line of symmetry, max/min value of the quadratic function.

f(x)=-2x+2x+8
I know I have to do completing the square to answer this but everytime i try to follow the steps I stumble hard! a(x-h)^2+k x= -b/2a
x=-2/2(2)=-2/4=-1/2 x+-1/2
for y f(-1/2)
2(-1/2)^2+2(-1/2)+8

That is all i managed and am certain none of it is right either.

3 answers

Okay I think I have this:
vertex: x=1/2 y=17/2
equation of line of symmetry: x=1/2
Maximum value of f(x)=17/2
Am I correct?

You are correct
Good for you!

Thanks Reiny