∫lnx/(x^n)dx
=∫lnx(1/1-n)(x^(1-n))'dx
=(1/1-n)[lnx(x^(1-n))-∫(1/x)(1/x^(n-1))dx]
=(1/1-n)[lnx(x^(1-n))-∫(1/x^n)dx]
=(1/1-n)[lnx(x^(1-n))-x^(-n+1)/(-n+1)]
=lnx(x^(1-n))/(1/1-n)+x^(-n+1)/(1-n)^2+C