高数课程妥媒血课件 镭理工大理>> 般地 f(x)=u(x)x)(u(x)>0) ∵In∫(x)=v(x)inu(x 又,Inf(x)= f∫(x) dx f(x) dx f(x)=∫(x):lnf(x) vaulx f(x=u(x)lv(x). Inu(x)+ ux Http://www.heut.edu.cn一般地 ( ) ( ) ( ( ) 0) ( ) f x = u x u x  v x ( ) ( ) 1 ln ( ) f x dx d f x f x dx d 又 =  ( ) ( ) ln f (x) dx d  f  x = f x  ] ( ) ( ) ( ) ( ) ( ) [ ( ) ln ( ) ( ) u x v x u x f x u x v x u x v x    =   +  ln f (x) = v(x)lnu(x)