Could someone explain how to do the following sample problems ?

Find the zeros of the function. Then sketch a graph of the function using x- intercepts, y-intercept and end behavior. 1. f(x) = x3 2x2 + 15:: Find the roots of the polynomial equations. 2. g(x) = x3 + 22x + 52 Write a polynomial function h of least degree that has rational coefcients, a leading coefcient of 1, and the given zeros. 3. 0,3,1 ~/7,2i Chapler 4 Page