Integrate (x+4)/(x^2+5x-6). I got 2/7ln(x+6)+5/7ln(x-1). But wolfram says 2/7ln(x+6)+5/7ln(1-x). Why is it 1-x instead of x-1??
usually the integral of 1/x is expressed as ln |x|
So, ln(x-1), ln(1-x) makes no difference. Actually, of course, I think it makes quite a difference, but wolfram pops up with this quite often.