Answer
$$\int (lnx)^{2}dx=x(lnx)^{2}-2xlnx+2x+C$$
Work Step by Step
${[x(lnx)^{2}]}'=(lnx)^{2}+2lnx$
$$\int (lnx)^{2}dx=x(lnx)^{2}-2\int lnx\,dx$$
${(x\,lnx)}'=lnx+1$
$$\int (lnx)^{2}dx=x(lnx)^{2}-2[xlnx-\int 1dx]$$
$$=x(lnx)^{2}-2xlnx+2x+C$$