当theta =dfrac (pi )(4)时，theta =dfrac (pi )(4)____;当theta =dfrac (pi )(4)时，theta =dfrac (pi )(4)______;当theta =dfrac (pi )(4)时，theta =dfrac (pi )(4)________。

当 theta =dfrac (pi )(3) 时，theta =dfrac (pi )(3)________ ，theta =dfrac (pi )(3)__

当theta =dfrac (pi )(3)时，theta =dfrac (pi )(3)______，theta =dfrac (pi )(3)______，

(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}4(cos )^4theta dtheta =__________________

[题目]已知 tan theta -tan (theta +dfrac (pi )(4))=7, 则 tan theta =-|||-()-|||-

(int )_(dfrac {pi )(4)}^dfrac (pi {2)}dtheta (int )_(0)^cot theta (r)^2cos theta

( 10 ) (int )_(0)^dfrac (pi {4)}(tan )^2theta dtheta ;

[例2](1)(2020·全国卷Ⅲ)已知 sin theta +sin (theta +dfrac (pi )(3))=1,-|||-则 sin (theta

(B) sqrt (dfrac {1cos theta )(g)} _ (C) pi sqrt (dfrac {1)(8)} . (D) pi sqrt (df

12.设曲线的极坐标方程为 rho =dfrac (1)(pi )(1-cos theta ), 求曲线在 theta =dfrac (pi )(2) 处的切线

dfrac (pi )(4) C. dfrac (pi )(2) D.π