Hello, I have this function: e^x/cos(x) Now I want to get the extremes. The TI-85 says, that are -pi/2 and pi/2. If I calculate this by myself, I get -5/4pi; -pi/4, 3/4pi. Some pc programmes are on my side, also. What is wrong. Does the TI-85 have a malfunction or is it me? Bye Michael