【单选题】
已知<img class="kfformula" src="20190809/1565322050560879.png" data-latex="A\left ( {0,-2} \right )"/>,<img class="kfformula" src="20190809/1565322050489966.png" data-latex="B\left ( {x,6} \right )"/>的中点坐标为<img class="kfformula" src="20190809/1565322050782302.png" data-latex="\left ( {-1,y} \right )"/>,则<img class="kfformula" src="20190809/1565322050701271.png" data-latex="x"/>,<img class="kfformula" src="20190809/1565322050277662.png" data-latex="y"/>的值分别为( )
①
<img class="kfformula" src="20190809/1565322050358526.png" data-latex="x=-4,y=-2"/>
②
<img class="kfformula" src="20190809/1565322050607462.png" data-latex="x=2,y=4"/>
③
<img class="kfformula" src="20190809/1565322050656212.png" data-latex="x=-4,y=25"/>
④
<img class="kfformula" src="20190809/1565322050205695.png" data-latex="x=-2,y=2"/>
【单选题】
两条平行直线<img class="kfformula" src="20190809/1565322829875215.png" data-latex="3x+4y-7=0"/>和<img class="kfformula" src="20190809/1565322829154016.png" data-latex="3x+4y+8=0"/>之间的距离是( )
①
<img class="kfformula" src="20190809/1565322829886592.png" data-latex="3"/>
②
<img class="kfformula" src="20190809/1565322829721740.png" data-latex="3\sqrt {2}"/>
③
<img class="kfformula" src="20190809/1565322829406438.png" data-latex="15"/>
④
<img class="kfformula" src="20190809/1565322829833725.png" data-latex="\frac {1} {5}" width="87" height="63"/>
【单选题】
在正方体<img class="kfformula" src="20190809/1565328255613453.png" data-latex="ABCD\_ {A}_{1}{B}_{1}{C}_{1}{D}_{1}"/>中,<img class="kfformula" src="20190809/1565328255952220.png" data-latex="{A}_{1}B"/>与<img class="kfformula" src="20190809/1565328255653689.png" data-latex="AC"/>所成的角是( )
【单选题】
一个球的半径是2cm,则它的球面面积和体积分别为( )
①
<img class="kfformula" src="20190809/1565328822421480.png" data-latex="8\pi ,\frac {16} {3}\pi "/>
②
<img class="kfformula" src="20190809/1565328822199687.png" data-latex="16\pi ,\frac {32} {3}\pi "/>
③
<img class="kfformula" src="20190809/1565328822100543.png" data-latex="16\pi ,\frac {16} {3}\pi "/>
④
<img class="kfformula" src="20190809/1565328822809093.png" data-latex="8\pi ,\frac {32} {3}\pi "/>
【单选题】
正五棱锥的底面积是<img class="kfformula" src="20190809/1565328530277328.png" data-latex="26{cm}^{2}"/>,高是<img class="kfformula" src="20190809/1565328530106797.png" data-latex="6cm"/>,则其体积是( )。
①
<img class="kfformula" src="20190809/1565328531591499.png" data-latex="104{cm}^{3}"/>
②
<img class="kfformula" src="20190809/1565328531884474.png" data-latex="{52cm}^{3}"/>
③
<img class="kfformula" src="20190809/1565328531242148.png" data-latex="78{cm}^{3}"/>
④
<img class="kfformula" src="20190809/1565328531496628.png" data-latex="156{cm}^{3}"/>
【单选题】
有100张卡片(从1号到100号),从中任取一张,取到的卡号是7的倍数的概率为( )
①
<img class="kfformula" src="20190809/1565330760695228.png" data-latex="\frac {7} {50}" width="75" height="53"/>
②
<img class="kfformula" src="20190809/1565330760810107.png" data-latex="\frac {3} {20}" width="68" height="53"/>
③
<img class="kfformula" src="20190809/1565330760716247.png" data-latex="\frac {7} {100}" width="76" height="53"/>
④
<img class="kfformula" src="20190809/1565330760831846.png" data-latex="\frac {7} {48}" width="68" height="53"/>
【单选题】
一个班级有12个班,每个班同学以1~50排学号,为了交流学习经验,要求每班学号为14的同学留下交流,这里运用的是( )
【单选题】
数据70,71,72,73的标准差是( )
①
<img class="kfformula" src="20190809/1565330298796439.png" data-latex="\sqrt {2}"/>
②
<img class="kfformula" src="20190809/1565330298960506.png" data-latex="\frac {\sqrt {5}} {2}" width="77" height="66"/>
③
<img class="kfformula" src="20190809/1565330298946541.png" data-latex="2"/>
④
<img class="kfformula" src="20190809/1565330298247161.png" data-latex="\frac {5} {3}" width="84" height="70"/>