【单选题】
正四棱锥底面边长是2,高是1,则斜高是()
①
<img class="kfformula" src="20190809/1565327137897917.png" data-latex="\sqrt {2}"/>
②
<img class="kfformula" src="20190809/1565327137411071.png" data-latex="\sqrt {5}"/>
③
<img class="kfformula" src="20190809/1565327137707931.png" data-latex="2"/>
④
<img class="kfformula" src="20190809/1565327137840495.png" data-latex="\sqrt {3}"/>
【单选题】
抛掷一个骰子,点数大于3的概率为( )
①
<img src="20190823/1566541454394535.jpg" title="1566541454394535.jpg" alt="图片12.jpg" width="17" height="45"/>
②
<img src="20190823/1566541464278744.jpg" title="1566541464278744.jpg" alt="图片13.jpg" width="16" height="20"/>
③
<img src="20190823/1566541443582779.jpg" title="1566541443582779.jpg" alt="图片11.jpg" width="16" height="44"/>
④
<img src="20190823/1566541432696403.jpg" title="1566541432696403.jpg" alt="图片10.jpg" width="16" height="43"/>
【单选题】
等差数列<img class="kfformula" src="20190809/1565317844150977.png" data-latex="\left \{ {{a}_{n}} \right \} "/>的首项<img class="kfformula" src="20190809/1565317844698638.png" data-latex="{a}_{1}=-2"/>,<img class="kfformula" src="20190809/1565317844536248.png" data-latex="{S}_{3}=3"/>,那么( )
①
<img class="kfformula" src="20190809/1565317844862924.png" data-latex="d=3"/>
②
<img class="kfformula" src="20190809/1565317844935823.png" data-latex="d=2"/>
③
<img class="kfformula" src="20190809/1565317844903124.png" data-latex="d=-2"/>
④
<img class="kfformula" src="20190809/1565317844953331.png" data-latex="d=-3"/>