cos2x=cos*2x-sin*2x cot*2x=csc*2x-1 cotx的导数=-csc*2x
∫(cos2x/sin^2x)dx=∫cos*2x-sin*2x/sin^2xdx 经过化简得 =∫cot*2xdx-∫1dx =∫csc*2xdx-∫1dx-∫1dx =-cotx-2x+c
cos2x=cos*2x-sin*2x cot*2x=csc*2x-1 cotx的导数=-csc*2x
∫(cos2x/sin^2x)dx=∫cos*2x-sin*2x/sin^2xdx 经过化简得 =∫cot*2xdx-∫1dx =∫csc*2xdx-∫1dx-∫1dx =-cotx-2x+c