Question

How do you use the remainder theorem to find P(-3) for `P(x) = x^3 + 3x^2 - x - 8`?

Answer 1

It is `P(-3)=-5`

Explanation:

In order to find the value of `P(-3)` you need to divide the P(x) with `x+3` hence

`P(x)=x^3+3x^2-x-8=(x+3)*k(x)+q(x)`

or `x^3+3x^2-x-8=(x^2-1)*(x+3)-5`

Hence the `P(-3)=-5`