I can do a and b for you but im unsure about c and d. I'm sorry :((
a. x = 2
It is the only point that hits the x axis, thus making it a zero of f(x).
b. substitute 2 for x in the original equation and it should equal 0.
f(x)= x^3 - 2x - 4
f(x)= 2^3 - 2(2) -4
f(x)= 8 - 4 - 4
f(x)= 0
