下列等式成立的是

A lg|x| B <img width="33" height="25" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175551_3373.jpg" /> C cotx D <img width="61" height="13" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175552_3933.jpg" />

A e B 1 C 1+e2 D 1n2

A 有极小值 B 有极大值 C 既有极小值又有极大值 D 无极值

A <img width="12" height="25" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175559_1812.jpg" /> B 0 C <img width="25" height="25" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175600_3842.jpg" /> D <img width="12" height="25" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175601_4156.jpg" />

A <img width="105" height="27" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175602_5884.jpg" /> B <img width="136" height="27" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175603_6199.jpg" /> C <img width="151" height="27" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175604_7748.jpg" /> D <img width="79" height="27" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175605_8686.jpg" />

A <img width="50" height="27" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175606_9780.jpg" /> B <img width="71" height="27" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175608_1030.jpg" /> C <img width="59" height="32" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175609_3061.jpg" /> D <img width="61" height="27" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175610_3061.jpg" />

A 球面 B 旋转抛物面 C 圆柱面 D 圆锥面

A <img width="57" height="32" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175612_4937.jpg" /> B <img width="47" height="32" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175613_7124.jpg" /> C <img width="36" height="32" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175614_6499.jpg" /> D <img width="47" height="32" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175615_9469.jpg" />

A y*=Aex B y*=Axex C y*=2ex D y*=ex