1. [-/10 Points] DETAILS MY NOTES a. Calculate the volume of the solid of revolution created by rotating the curve y = 3 + 6exp (-5 x) about the x-axis, for x between 2 and 4. Volume : b. The equation of a circle of radius r, centered at the origin (0,0), is given by r=xty . 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.) . Suppose we wanted to set up the following integral so that V gives the volume of a sphere of radius r v = [ 's( ) do What would a, b and f(x) be? a = to to b = f ( x ) = (WebAssign note: remember that you enter 7 as pi ) . Carry out the integration, and calculate the value of V in terms of r. V = symbolic formatting help