3.[单选题]设C为 =(e)^itheta (theta )^-dfrac (pi {2)}=dfrac (pi )(2) 的一段,则-|||-(int )_(c)^1|=|dz= ()-|||-A) i-|||-B -21-|||-C -1-|||-D 2i

3.要使函数φ(x )= ,dfrac {pi )(2)] (B)[π,2π] (C) [ 0,dfrac (pi )(2)] (D) [ dfrac

设=(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}dfrac (sin x)(1+{x)^2}(cos )^4xdx, =(in

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

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)}dfrac (|x|sin x)(1+{cos )^3x}dx=(int )_(-

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

设(x)=sin x, 则(dfrac (pi )(2))= __-|||-_.-|||-A cos dfrac (pi )(2)-|||-B o-|||-C-

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

2.计算下列定积分:-|||-(1) (int )_(dfrac {pi )(3)}^pi sin (x+dfrac (pi )(3))dx;-|||-(2)