From the Quotient-Remainder Theorem follows that for every f(x) there exist unique polynomials q(x) and r(x) such that: , where r(x) is called remainder. If r(x)=0, then f(x)=h(x)q(x) and q(x) is adivisor. If q(x) is of form q(x)=x-a, then a is a root of f(x).