find the value of a, if x-a is a factor of x^3-a^2x+x+2
I see about 9 questions that you posted all dealing with the factor and remainder theorems.
You have shown no effort on your part or let us know where you difficulties are.
They all basically follow these two concepts :
if for some f(x) , x-a is a factor, then f(a) = 0
if for some f(x), division by x-a leaves a remainder of k , then f(a) = k