1. The problem statement, all variables and given/known data i am trying to apprixmate the surface area of a hemisphere. i am approximating by cutting the sphere into cylinders of different radius, and using their curved surface area to approximate. each cylinder will have a height of r.cos.theta and radius of r.sin.theta. so the surface area should be = integral [pi/2 to 0] (2.pi * r.sin.theta * r.cos.theta * d.theta)?? but that gives me -pi r^2 which is wrong... anyidea where i went wrong?