Please check my answers.

Find the y-intercept of the polynomial function.

f(x) = -x2 - 2x + 8
I got:y=8

f(x) = (x + 1)(x - 6)(x - 1)2
I got: y=-6

f(x) = -x2(x + 6)(x2 - 1)
I got:y=0