II. Use the summation formulas below to evaluate the given integrals. n n(n + 1) n(n + 1)(2n + 1) n(n + 1)]2 : 12 = iv) 1- 3 = i ) 1 = n ii) K = iii) 2 6 2 k=1 *=1 k =1 *= 1 1 1 7) V3dx 8) (x + 1)3 dx 1