求 int(cos2x)/(cos^2xsin^2x) dx 。

求下列不定积分:-|||-(22) int dfrac (cos 2x)({cos )^2x(sin )^2x}dx ;

.int dfrac (1+{cos )^2x}(1+cos 2x)dx

int dfrac (cos 2x)(cos x+sin x)dx

int (e)^-2xsin dfrac (x)(2)dx; ;

)int dfrac (1)({cos )^2x(sin )^2x}dx.

(int )_(0)^dfrac (pi {4)}dfrac (x)(1+cos 2x)dx=( ) .(int )_(0)^dfrac (pi {4)}dfr

(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}((cos )^2x+dfrac (xcos x)(1+{cos )^2x})dx

int dfrac (sin x)(1+{cos )^2x}dx=-|||-__

( 20 int dfrac (dx)(1+cos 2x) ;

int dfrac (1)(1+cos 2x)dx=______.______.