d x 解 COSx d d (sin coSx cosx J1-sin'x +sinx +c SInx 1+sinx +c Inlsecx+tanx+C 202//302021/1/30 12  x dx cos [例6]    − = = x d x dx x x dx x 2 2 1 sin (sin ) cos cos cos 1 C x x + − + = 1 sin 1 sin ln 2 1 C x x + + = cos 1 sin ln [解] = ln sec x + tan x + C