【单选题】
在下列函数中,( )在指定区域内是单调减少的函数
①
<img src=https://huaweicloudobs.ahjxjy.cn/087E58F5FC3F975668C0B235653FCD10.png title={KZ%~M7WDSN86IJUUVMFVK7.png alt={KZ%~M7WDSN86IJUUVMFVK7.png/>
②
<img src=https://huaweicloudobs.ahjxjy.cn/44E8F1CC8CEFD9400C2FFE917B1F2D7D.png title=AX_S_DL_ZW}QZK]}]L`SP{7.png alt=AX_S_DL_ZW}QZK]}]L`SP{7.png/>
③
<img src=https://huaweicloudobs.ahjxjy.cn/743F6FDBC8ECBD9A330B63164AFD4FF7.png title=F_M`]4_A]{N{~J$WD8C(Z9O.png alt=F_M`]4_A]{N{~J$WD8C(Z9O.png/>
④
<img src=https://huaweicloudobs.ahjxjy.cn/7A6F6928A94857244FFE19169BD6C0F3.png title=VECWQKKE81JSICN(}}47RK5.png alt=VECWQKKE81JSICN(}}47RK5.png/>
【单选题】
下列函数中,在区间<img class="kfformula" src="20190808/1565255863544549.png" data-latex="\left ( {-\infty ,+\infty } \right )"/>内为增函数的是( )
①
<img class="kfformula" src="20190808/1565255863279980.png" data-latex="y=2-x"/>
②
<img class="kfformula" src="20190808/1565255863845028.png" data-latex="y={3}^{x}"/>
③
<img class="kfformula" src="20190808/1565255863797150.png" data-latex="y={x}^{-2}"/>
④
<img class="kfformula" src="20190808/1565255863844363.png" data-latex="y={log}_{0.3}x"/>