∫cosx/(1+cosx)dx
=2∫[cos^2(x/2)-sin^2(x/2)]/[cos^2(x/2)]dx
=2∫[1-tan^2(x/2)]dx
=2∫[2-sec^2(x/2)]dx
=4x-4tan(x/2)+C
你的好評是我前進(jìn)的動力.
我在沙漠中喝著可口可樂,唱著卡拉ok,騎著獅子趕著螞蟻,手中拿著鍵盤為你答題!分子上的cosx哪來的呢？分子上沒有cosx的吧看錯了，下面的1+cosx=2[cos(x/2)]^21/(1+cosx)=0.5[sec(x/2)]^2 ∫dx/(1+cosx)=∫0.5[sec(x/2)]^2dx=∫[sec(x/2)]^2d0.5x=∫dtan(x/2)=tan(x/2)+c請好評~~