求不定积分axln(b/x)dx,ab为常数

∫ axln(b/x) dx
=(a/2) ∫ ln(b/x) dx^2
=(a/2)[ x^2.ln(b/x) + ∫ (b/ x^2) ( x^2/(b/x)) dx ]
=(a/2)[ x^2.ln(b/x) +∫ x dx ]
=(a/2)[ x^2.ln(b/x) - x^2/2 ] + C