What is the antiderivative of ln(x)^2?

1 Answer
Feb 23, 2017

int (lnx)^2dx = x(ln^2x -2lnx + 2 ) + C

Explanation:

Integrate by parts, using dx as differential part:

int (lnx)^2dx = xln^2x -int x d(ln^2x)

int (lnx)^2dx = xln^2x - 2int x lnx/xdx

int (lnx)^2dx = xln^2x - 2int lnxdx

Integrating by parts again:

int (lnx)^2dx = xln^2x -2 xlnx + 2 int x d(lnx)

int (lnx)^2dx = xln^2x -2 xlnx + 2 int x dx/x

int (lnx)^2dx = xln^2x -2 xlnx + 2 int dx

int (lnx)^2dx = xln^2x -2 xlnx + 2 x + C

int (lnx)^2dx = x(ln^2x -2lnx + 2 ) + C