I don't understand why I'm getting a "non-real result" from the calculation when I enter x=0. Why is that occurring? It should be the same regardless of which form it's written in.
My TI 89 Platinum is returning ln(abs(cos(x))/abs(sin(x)-1)) for integral sec(x)dx. It's supposed to return ln(abs(tan(x)+sec(x)) or ln(abs(sin(x)+1)/abs(cos(x))). If you enter x=0, you get 'undefined' the way my TI 89 is doing it. It's supposed to return 0. Is this a computation error or...