F(theta)= (cos(theta pi))^ -2 find 2nd derivative of F(2). I have tried it different ways. I have worked it from the original to the 1st then 2nd derivative of theta. At the end I plugged 2 in and that was no good. I tried taking derivative of 2 from the 1st to the second and that hasnt worked either. Can some please explain where I am wrong. If i replace theta with 2 then would it not be (cos(2pi))^ -2 and wouldn't that be the same as 1/((cos(2 pi))^2 and then use the quotient rule for the 1st derivative and go from there? Who knows my brain is fried and help would be awesome.