∫x√(x^2+1)dx
=(1/2)∫√(x^2+1)dx^2
=(1/2)∫(x^2+1)^(1/2)d(x^2+1)
=(1/2)*[(x^2+1)^(1/2+1)/(1/2+1)]+C
=(1/3)(x^2+1)^(3/2)+C
=(1/3)*(x^2+1)/√(x^2+1)+C
∫x√(x^2+1)dx
=(1/2)∫√(x^2+1)dx^2
=(1/2)∫(x^2+1)^(1/2)d(x^2+1)
=(1/2)*[(x^2+1)^(1/2+1)/(1/2+1)]+C
=(1/3)(x^2+1)^(3/2)+C
=(1/3)*(x^2+1)/√(x^2+1)+C