1. The problem statement, all variables and given/known data Problem shown as image jan2010 Q5.jpg Q5. a) 2. Relevant equations Also shown in image 3. The attempt at a solution Made a cut between A and the z-line, so ∑M = 0 = M - wx(x/2) = M - (wx2)/2 ⇒ M = (wx2)/2 and d2y/dx2 = -M/EI ∴ d2y/dx2 = - (wx2)/2EI So dy/dx = ∫ d2y/dx2 dx = -w/2EI ∫ x2 dx = -wx3/6EI + c1 I was fine up to this point. My answer here agrees with the answer in the question ( equation 5.2) as x = L. So what I got next: y = ∫ dy/dx dx = -w/6EI ∫ x3 dx + ∫ c1 dx = -wx4/24EI + c1x + c2 Letting x = L dy/dx = -wL3/6EI + c1 (as in the question) and y = -wL4/24EI + c1L + c2 (which is different to the answer given in the question) How/why is the answer to equation 5.2 wL4/8EI ?? I probably made a silly mistake somewhere or I'm just too tired :P Thanks for any help.