推论2 I(x=f(x)(x)-(x)+1(x)(x):()+…+(x)(x)f(x 特别要注意[Cl(x)=Cu'(x) (3)中的∫(x)=1时, g(x) g(x g2(x) 例5已知 y=x+3mx-3wx+inz-a",求边 d 解 3 =2x+-+sinx 小y 丌3 6 2·-+-+3sin dx 2兀+-+35 1 2 1 2 1 2 1 [ ( )] ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ). n i n n n i f x f x f x f x f x f x f x f x f x f x =      = + + + 例5.已知 2 2 100 3ln 3cos sin , 2 x dy y x x x a dx   = = + − + − 求 2 1 ( ) (3) ( ) 1 [ ] ( ) ( ) g x f x g x g x  中的 = = − 时，  特别要注意 [ ( )] ( ). Cu x C u x   = 3 2 3sin dy x x dx x 解 = + + 2 2 3 6 2 3sin 3 2 2 x dy dx        =  + + = + + = 推论2