Integral of ln x

How to integrate ln x. (Natural logarithm of x)

[angelmendez-rivera]

Another method is to let y = ln(x), hence x = exp(y), and dx = exp(y)·dy. Therefore, the integrand in y is y·exp(y), and the antiderivative of this is probably one people have already encountered: y·exp(y) – exp(y) = exp(y)·(y – 1) = x·[ln(x) – 1].