Please help with both 12 and 13.

12. (4 points, 2 points each) Let p(x) be a polynomial ofdegree n, that is, p(x)-=0 air. (Goodrich, p. 190) a. Describe a simple O(n') time method for computing po). b. Now consider a rewriting of pr) as p(x) = ao +x(a1 + x(a2 + x(a; + + x(an-l + xan) ))), which is known as Horner's method. Using the big-Oh notation, characterize the number of arithmetic operations this method executes 13. (6 points, 2 points each) Evaluate the following sums: (Weiss, p. 47) i=0 41 i2 47 C