How To: Factor & find zeros of a polynomial

This is the video about how to Factor & find zeros of a polynomial. How did I know that x=1 and x=-1 were roots of the polynomial. Suppose the polynomial has a rational root, let's call it. I will assume that p and q are co prime, i.e., the fraction is reduced to lowest terms. What we will be doing is somewhat similar to "factoring by guessing" of quadratic polynomials. Since is assumed to be a root of P(x), we know that if we multiply both sides by, we obtain: Transfer them to the other side and factor out a p on the left: Now the left side is divisible by p; consequently, is divisible by p. Since p does not divide q, it does not divide, so p divides 2, i.e,