Hi, I'm using KA Stroud 6th edition (for anyone with the same book, P407) and there is a example question where I just can't seem to get the answer they have suggested: 1. The problem statement, all variables and given/known data Question: Determine the value of I = ∫(4x3-6x2-16x+4) dx when x = -2, given that at x = 3, I = -13 Their answer is when x = -2, I = 12. 3. The attempt at a solution I found the integral: I = ∫(4x3-6x2-16x+4) dx = x4-2x3-8x2+4x + C and then substituted x for 3 and getting: -13 = -33 + C thus: C = 20 Now when I replace x with -2, plus the constant, I get: -24-2(-2)3-8(-2)2+4(-2) + 20 = -20 I'm a few days into Integrals so I feel I may be doing something daft? Many thanks.