a. Calculate the volume of the solid of revolution created by rotating the curve y = 3+ 5 exp (-2 x) about the x-axis, for x between 2 and 5. Volume : b. The equation of a circle of radius r, centered at the origin (0,0), is given by 12 = x2 + y . Rearrange this equation to find a formula for y in terms of x and r. (Take the positive root.) Equation: y = . What solid of revolution is swept out if this curve is rotated around the x axis, and x is allowed to vary between -r and r? (You do not need to enter this answer into WebAssign.) o Suppose we wanted to set up the following integral so that V gives the volume of a sphere of radius r v = / f (x) dx What would a, b and f(x) be? a = b = f( X ) = (WebAssign note: remember that you enter 7 as pi ) o Carry out the integration, and calculate the value of V in terms of r. V =