Question

In remainder theorem, on dividing a polynomial p(x) by x-a, the remainder will be p(a). Why do we substitute x as a ?

Answer 1

Here p(x) is the polynomial and it is divided by x-a.
                      In order to find x from the polynomial;
                                 x-a = 0
                                   x = a. 
So in the place of x we substitute a.
 *If f(x) is divided by x-2 then the remainder is f(2)
                        bcoz x-2 = 0
                                    x = 2. That's how we do it........