11 单选 -|||-lim _(xarrow {pi )_(+)}dfrac (sqrt {1+cos x)}(sin x)= ()-|||-○
_(n)=((-1))^n+1dfrac (1)(sqrt {n)}-|||-C. _(n)=sin dfrac (npi )(2)-|||-D. _(n)=d
+dfrac (sin npi )(n+dfrac {1)(n)}]
(int )_(0)^dfrac (pi {4)}dfrac (x)(1+cos 2x)dx=( ) .(int )_(0)^dfrac (pi {4)}dfr
+dfrac (1)({n)^2+npi })=1;;
(B) sqrt (dfrac {1cos theta )(g)} _ (C) pi sqrt (dfrac {1)(8)} . (D) pi sqrt (df
int dfrac (1)(1+cos 2x)dx=______.______.
+dfrac (1)({n)^2+npi })= 1..
( 20 int dfrac (dx)(1+cos 2x) ;
.int dfrac (1+{cos )^2x}(1+cos 2x)dx