A <img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084036153615.gif" />     B ±<img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084069856985.gif" />      C ±<img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084096859685.gif" />      D <img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084035493549.gif" />

A <img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084080218021.gif" />       B <img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084061216121.gif" />       C ±<img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084029272927.gif" />       D <img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084173307330.gif" />

A <img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084980548054.gif" />       B <img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084987918791.gif" />        C <img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084962906290.gif" />        D <img alt="" src="https://www.beizhujiaoyu.com/uploads/202208/20120921084921772177.gif" />

A f(x+2π)=f(x)               B f(π-x)=f(x) C f(-x)=f(x)                 D  f(-x)=-f(x)