Find dy/dx and d^2y/dx^2 as functions of x and y given that xy^2+y=1.

Find the length of the given curve: x=3t^2, y=3t^3-t t=[0,1]

Find the surface area when the following parametric curve is rotated about the x-axis by 360 degrees: x=t-t^2/2, y=4/3t^3/2 t=[0,1]

I am starting into revision for my exams which are looming! And these are a few questions which have stumped me. Any help would be much appreciated