I am having some problems with my Ti-89. I am familiar with all the settings under "Mode." However, when integrating the function 1/(sinx) the calculator returns the form "ln[(sinx)/(cosx-1)]" and NOT the form "ln[tan(x/2)]." I am completely unable to get the calculator to return the other form of the integral. I have even used other Ti-89s and they return the second form and I cannot see any difference in the settings. Can anyone help?