A 0 B 1 C ∞ D 不存在但不是∞

A -1 B 0 C <img width="12" height="25" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175706_1499.jpg" /> D 1

A y=|x| B <img width="39" height="14" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175707_4156.jpg" /> C y=x3 D y=lnx

A 单调减少 B 单调增加 C 无最大值 D 无最小值

A y=2 B y=-2 C y=1 D y=-1

A sinx B cosx C -cosx D -sinx

A 0 B 1 C 2 D -1

A (1，0) B (1，2) C (-3，0) D (-3，2)

A <img width="35" height="32" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175716_2436.jpg" /> B <img width="90" height="33" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175717_2593.jpg" /> C <img width="48" height="33" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175718_4313.jpg" /> D <img width="50" height="32" src="https://www.beizhujiaoyu.com/uploads/202208/20220324175719_4469.jpg" />