Question

min/max point
minimum or maximum
f(x)=2x^2+8x-2

a=2
x=(-b)/(2a)=(-8)/(2)(2)=-4
x=-4
y=2(-4)^2+8(-4)-2
2(16)-32-2
32-32-2
y=-2
(-4,-2)
axis of symmetry is x=-4
range[-2,oo]
minimum value -2

Answer 1

I think you messed up when trying to find the axis of symmetry. There's a small calculation error there and it seems to have thrown off all your answers. However, your work overall is correct.

Answer 2

when you used the calculator to find (-8)/(2)(2) you did not consider the order of operations you must multiply 2 by 2 before you divide -8 by the answer, otherwise your method is correct

Answer 3

My range changes to -10 and the axis is x=-2, and min value is -10?

Answer 4

Yes.