⑩天掌 Teaching Plan on Advanced Mathematics y=cosx·Inx+snx y= y(cos x In x+sinx·-) sInx sIn x (cos x Inx 一般地 ∫(x)=u(x) v(x) (u(x)>0) In f(x=v(x)Inu(x) 又∵,Inf(x) f(r)d vaTianjin Polytechnic University Teaching Plan on Advanced Mathematics x y x x x y 1 cos ln sin 1  =  +  ) 1 (cos ln sin x  y = y x  x + x  ) sin (cos ln sin x x x x x x =  + 一般地 ( ) ( ) ( ( ) 0) ( ) f x = u x u x  v x  ln f (x) = v(x)lnu(x) ( ) ( ) 1 ln ( ) f x dx d f x f x dx d 又 = 