To do this problem, if we want to go around the X axis, we know it's going to be a DX, so our bounds are going to be 2π. We've got to figure out from Pi 5th to π force that was given for going around our X axis. The radius is going to be our Y or our height, and so it's going to be tangent X square root 1 plus our DYDX. So our dy DX. The derivative of tangent is secant squared. So when we square that, we get secant squared X ^2 DX. So 2π Pi 5th to Pi 4th tangent X square root 1 plus secant to the 4th X DX. Now we don't know how to solve that, and so at this point we're going to grab our calculators. That's what it says to do a numerical solve is we don't know how to solve this, so we're going to use our calculators to solve it. When we plug it in we get 1.71.