Here an AP Physics problem that's really bugging me. 1. The problem statement, all variables and given/known data A particle moves along the parabola with equation y = .5x^2 part a) I believe I did this correct. part b) Suppose that the particle moves with a velocity whose x-component is given by vx = c / (1 + x^2)^.5 Show that the particle's speed is constant. Below I have images of the question and my attempted work. I think maybe for the first half of my work I was in the right direction; I got y in terms of t, and I was going to find the derivative to show that there is no acceleration, but I couldn't get the equation to equal y, and I ultimately became confused and went off track. 3. The attempt at a solution http://img363.imageshack.us/img363/7313/scanqa9.th.jpg [Broken]http://g.imageshack.us/thpix.php [Broken] http://img218.imageshack.us/img218/2346/scan0001fu2.th.jpg [Broken]http://g.imageshack.us/thpix.php [Broken] I know; my work is a mess.