1. The problem statement, all variables and given/known data x = t^3, y = (3t^2)/2 0<= t <= √3 3. The attempt at a solution dx/dt = 3t^2 dy/dt = 3t step 1. √((3t^2)^2 + (3t)^2) step 2. 3t^2 + 3t (the book says I can't do that, I don't see why) step 3. insert √3 into t Here's the books solution I understand u substitution but I don't see why it's necessary here. I don't why my method does not follow all the rules.