Calculus Integral question!?

I have a question about one of my problems. Integral 1 at the high end and 0 at the low end then x/1+2x^2 dx is the problem (sorry hard to write it on here. To clarify, its the integral sign with 1 at the top and 0 at the bottom and its next to the x/1+2x^2 dx). I'm at the part where its 1/4ln(3)-1/4ln1. I know the answer is 1/4ln3 but why? does the -1/4ln1 not do anything? Has to do with the formula integral b a the top, a at the bottom f(x)dx=F(b)-F(a). Help!