∫ln(x+√(1+x^2))dx=xln(x+√(1+x^2))-∫xdln(x+√(1+x^2) =xln(x+√(1+x^2)-√(1+x^2)+C ∫[0,1]ln(x+√(1+x^2)dx=ln(1+√2)-√2+1
