【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】
<img class="kfformula" src="20190808/1565256537299613.png" data-latex="\left ( {{log}_{3}2} \right )\cdot \left ( {{log}_{2}27} \right )="/>( )
【单选题】
如果<img class="kfformula" src="20190808/1565251013539366.png" data-latex="ab"/>,那么下列不等式正确的是( )
①
<img class="kfformula" src="20190808/1565251013586057.png" data-latex="\frac {1} {2}a\frac {1} {2}b"/>
②
<img class="kfformula" src="20190808/1565251013931183.png" data-latex="-3a-3b"/>
③
<img class="kfformula" src="20190808/1565251013130324.png" data-latex="5a5b"/>
④
<img class="kfformula" src="20190808/1565251013738499.png" data-latex="a-2b-2"/>
【单选题】
在数列<img class="kfformula" src="20190809/1565316783973080.png" data-latex="\left \{ {{a}_{n}} \right \} "/>中,前<img class="kfformula" src="20190809/1565316783992384.png" data-latex="n"/>项和公式是<img class="kfformula" src="20190809/1565316783683277.png" data-latex="{s}_{n}=4{n}^{2}-n"/>,那么<img class="kfformula" src="20190809/1565316783325652.png" data-latex="{a}_{2}"/>为( )
【单选题】
已知<img class="kfformula" src="20190809/1565317530438878.png" data-latex="a,b,c"/>是公比为2的等比数列,则<img class="kfformula" src="20190809/1565317530533557.png" data-latex="\frac {{b}^{2}} {ac}" width="74" height="64"/>等于( )
①
<img class="kfformula" src="20190809/1565317530127108.png" data-latex="\frac {1} {2}"/>
②
<img class="kfformula" src="20190809/1565317530414229.png" data-latex="1"/>
③
<img class="kfformula" src="20190809/1565317530771921.png" data-latex="\frac {1} {8}"/>
④
<img class="kfformula" src="20190809/1565317530451678.png" data-latex="\frac {1} {4}"/>
【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】
两直线<img class="kfformula" src="20190809/1565322635666732.png" data-latex="3x+y-1=0"/>和<img class="kfformula" src="20190809/1565322635986296.png" data-latex="x+3y-1=0"/>的位置关系是( )
【单选题】
某公司销售某产品的利润函数为<img class="kfformula" src="20190808/1565255089180842.png" data-latex="y=-100{x}^{2}+1500x-5400"/>(<img class="kfformula" src="20190808/1565255089940036.png" data-latex="x" width="61" height="43"/>为销售价格),当零售价为7.5元时,销售利润最大,最大利润为( )
【单选题】
检验<img class="kfformula" src="20200629/1593438124440556.png" data-latex="{SO}_{2}" width="46" height="34"/>中是否有<img class="kfformula" src="20200629/1593438124677903.png" data-latex="{CO}_{2}" width="41" height="31"/>,应采取的措施是()。
②
通过<img class="kfformula" src="20200629/1593438124664740.png" data-latex="{Ba(OH)}_{2}" width="75" height="29"/>溶液再通过石灰水
④
通过<img class="kfformula" src="20200629/1593438124648423.png" data-latex="{KMnO}_{4}" width="70" height="27"/>酸性溶液再通过石灰水
【单选题】
今有360本图书借给学生阅读,每人9本,则余下的书数<img class="kfformula" src="20190924/1569292387333325.png" data-latex="y"/>(本)和学生数<img class="kfformula" src="20190924/1569292387869597.png" data-latex="x"/>(个)之间的函数关系式为( )
①
<img class="kfformula" src="20190924/1569292387325349.png" data-latex="y=40/x"/>
②
<img class="kfformula" src="20190924/1569292387912197.png" data-latex="y=9*x"/>
③
<img class="kfformula" src="20190924/1569292387266041.png" data-latex="y=360-9x"/>
④
<img class="kfformula" src="20190924/1569292387456376.png" data-latex="y=360+9x"/>