设 是曲线 ，其周长为 ，则 的值为2s 。（ ）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/7d30d24bbe60402e89731229cc2c009c.png
举一反三
- 设区域，则的值为。( ）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/468d5951e23a436ba9cd1954573d5aef.png
- 设是从到的单位圆弧，则的值为。( )http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/d1d41bb04c5f4b88ba454f29dd0ee649.png
- 内压球形容器的应力为： A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/7a7e20156c8c4502840fc258ffe21c74.png"> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/6b137ba6e7464b2c8122eced2a3d45cd.png"> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/3c032f5116a04b288400df17925e39c2.png"> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/85ca21668f4045e2b864897bc3795fdf.png">
- 设是圆周，方向为逆时针方向，则。（ ）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/3888f5f3fd4d48bb95a479c97a4ad93a.png
- 设是球面与平面的交线，则的值为。（ ）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/9d7cfd7539a2408bbe41ddb5a0407d55.png