(a) For the polynomial function f(x)=3x5−2x+1, state its domain.
(b) Give a brief reason to justify that every polynomial function in one variable has the same domain as in part (a).
(c) Consider the polynomials p(x)=x4 and q(x)=x3. Explain, without detailed graph-drawing, why the range of p is [0,∞) whereas the range of q is R.