Find the area of the surface generated by revolving x=e t cost, y=e t sin t, 0t/2 above the x -axis. where, ds=(dx/dt)2+(dy/dt)2 dt Find

Find the area of the surface generated by revolving x=e^t cost, y=e^t sin t, 0≤t≤π/2 above the x-axis. 

where, ds=√(dx/dt)2+(dy/dt)2 dt

Find the area of the surface generated by revolving a = e' cos t, y= e' sin t, 0