a) If e^2-e^x

Find any stationary points on the curve. (Also how would I go about drawing this curve?)

b) The curve y=ln(x^2-3) crosses x axis at (2,0) and (-2,0). The normals at A and B meet at P. Find the coordinates of P.

c) If y=asinnx +bcosnx show that d^2y/dx^2+n^2y=0

thanks in advance