Let f(x)=x2−3x+2, g(x)=2x3+x−1 and h(x)=5−x.
(i) Form the polynomial P(x)=(f(x)+g(x))h(x) and simplify completely.
(ii) Determine the degree and the leading coefficient of P(x).
(iii) Find the value of P(1).
(iv) Confirm that the domain of P(x) is R.