1. The problem statement, all variables and given/known data If a solid is generated by rotating the line (x=4tan(y*pi/3)) on the y-axis. Find the volume between the area 0≤y≤1. 2. Relevant equations I know that, when slicing a section (A(x)), I will generate a circle. This gives me two of the dimensions (by using area of a circle formula; A=pi*r2). r=4tan(y*pi/3) Therefore, V= [itex]\int[/itex] pi*(4tan(y*pi/3))2 Lower Lim: 0, Upper lim:1 3. The attempt at a solution This should become: V = 16*pi [itex]\int[/itex] (tan(y*pi/3)2 Then, u = tan (y*pi/3) w = y*pi/3 V = 16*pi [itex]\int[/itex] (u2)(tan(w))(y*pi/3) then, V = (16pi) (tan(pi*y/3)3/3) (ln|cos(pi*y/3)|) (pi*y2/6) My calculator tells me i should end up with 4(3^(1/2) - pi) but I have no idea how. It's just this last step that is killing me.