2024年成考高起点《数学(理)》每日一练试题05月03日
<p class="introTit">单选题</p><p>1、已知集合M =(2,3,5,a),N =(1,3,4,b),若M∩N=(1,2,3),则a,b的值为
</p><ul><li>A:a=2,b=1</li><li>B:a=1,b=1</li><li>C:a=1,b= 2</li><li>D:a=1,b=5</li></ul><p>答 案:C</p><p>解 析:M∩N={2,3,5,a} ∩{1,3,4,6} ={1,2,3} 又因为M中无“1”元素,而有“a”元素,只有a=1
而N中无“2”元素,而有“b元素”,只有b=2
</p><p>2、如果点A(1,1)和B(2,4)关于直线y=kx+b对称,则k=()。</p><ul><li>A:-3</li><li>B:<img src='https://img2.meite.com/questions/202404/1966222d759cd91.png' /></li><li>C:<img src='https://img2.meite.com/questions/202404/1966222d7aed401.png' /></li><li>D:3</li></ul><p>答 案:B</p><p>解 析:本题主要考查的知识点为两垂直直线斜率的关系。直线AB的斜率为<img src="https://img2.meite.com/questions/202404/1966222d849e795.png" />点A、B关于直线y=kx+b对称,因此直线AB与其垂直,故3k=-1,得<img src="https://img2.meite.com/questions/202404/1966222d91b70b1.png" /></p><p>3、<img src="https://img2.meite.com/questions/202303/1564116591bffc0.png" />的展开式中,x<sup>2</sup>的系数为()</p><ul><li>A:20</li><li>B:10</li><li>C:5</li><li>D:1</li></ul><p>答 案:C</p><p>解 析:二项展开式的第二项为<img src="https://img2.meite.com/questions/202303/1564116a225f0b5.png" />,故展开式中的x<sup>2</sup>的系数为5.</p><p>4、设0<a<b<1,则下列正确的是
</p><ul><li>A:<img src='https://img2.meite.com/questions/202303/2864225b1e4a590.png' /></li><li>B:<img src='https://img2.meite.com/questions/202303/2864225b29000a7.png' /></li><li>C:<img src='https://img2.meite.com/questions/202303/2864225b2e590ed.png' /></li><li>D:<img src='https://img2.meite.com/questions/202303/2864225b34e87f0.png' /></li></ul><p>答 案:D</p><p>解 析:<img src="https://img2.meite.com/questions/202303/2864225e9994bba.png" /><img src="https://img2.meite.com/questions/202303/2864225ea183366.png" />
</p><p class="introTit">主观题</p><p>1、某工厂每月生产x台游戏机的收入为R(x)=<img src="https://img2.meite.com/questions/202303/28642259676bd4d.png" />+130x-206(百元),成本函数为C(x)=50x+100(百元),当每月生产多少台时,获利润最大?最大利润为多少?
</p><p>答 案:利润 =收入-成本, L(x)=R(x)-C(x)=<img src="https://img2.meite.com/questions/202303/28642259c06a284.png" />+130x-206-(50x+100)=<img src="https://img2.meite.com/questions/202303/28642259e2077b7.png" />+80x-306
法一:用二次函数<img src="https://img2.meite.com/questions/202303/28642259fb36916.png" />当a<0时有最大值
<img src="https://img2.meite.com/questions/202303/2864225a14ed5aa.png" />是开口向下的抛物线,有最大值
<img src="https://img2.meite.com/questions/202303/2864225a2c75330.png" />
法二:用导数来求解
<img src="https://img2.meite.com/questions/202303/2864225a43988b8.png" />
因为x=90是函数在定义域内唯一驻点
所以x=90是函数的极大值点,也是函数的最大值点,其最大值为L(90)=3294
</p><p>2、已知直线l的斜率为1,l过抛物线C:<img src="https://img2.meite.com/questions/202303/156411660ae04fb.png" />的焦点,且与C交于A,B两点.(I)求l与C的准线的交点坐标;<br />(II)求|AB|.</p><p>答 案:(I)C的焦点为<img src="https://img2.meite.com/questions/202303/1564116c40cf40a.png" />,准线为<img src="https://img2.meite.com/questions/202303/1564116c45024f5.png" />由题意得l的方程为<img src="https://img2.meite.com/questions/202303/1564116c5cf0409.png" />因此l与C的准线的交点坐标为<img src="https://img2.meite.com/questions/202303/1564116c7901a26.png" />(II)由<img src="https://img2.meite.com/questions/202303/1564116c9294ce9.png" />,得<img src="https://img2.meite.com/questions/202303/1564116c9d411f3.png" />设A(x1,y1),B(x2,y2),则<img src="https://img2.meite.com/questions/202303/1564116cd0bfaf7.png" />因此<img src="https://img2.meite.com/questions/202303/1564116ce1375a9.png" /></p><p>3、已知a,b,c成等差数列,a,b,c+1成等比数列.若b=6,求a和c.</p><p>答 案:由已知得<img src="https://img2.meite.com/questions/202303/1564116c009cc19.png" />解得<img src="https://img2.meite.com/questions/202303/1564116c0e039c1.png" /></p><p>4、建筑一个容积为8000<img src="https://img2.meite.com/questions/202303/2864224b406cbf6.png" />,深为6m的长方体蓄水池,池壁每<img src="https://img2.meite.com/questions/202303/2864224b5cac16d.png" />的造价为15元,池底每<img src="https://img2.meite.com/questions/202303/2864224b60ac28e.png" />的造价为30元。(I)把总造价y(元)表示为长x(m)的函数;(Ⅱ)求函数的定义域
</p><p>答 案:<img src="https://img2.meite.com/questions/202303/2864224be4311f4.png" /><img src="https://img2.meite.com/questions/202303/2864224bee67713.png" /></p><p class="introTit">填空题</p><p>1、函数<img src="https://img2.meite.com/questions/202303/2864225857f0d64.png" />的图像与坐标轴的交点共有()
</p><p>答 案:2</p><p>解 析:当x=0时,y=<img src="https://img2.meite.com/questions/202303/286422587f2a68b.png" />-2=-1,故函数与y轴交于(0,-1)点,令y=0,则有<img src="https://img2.meite.com/questions/202303/28642258b372965.png" />故函数与x轴交于(1,0) 点,因此函数 <img src="https://img2.meite.com/questions/202303/28642258c6c51c8.png" />与坐标轴的交点共有 2个.</p><p>2、<img src="https://img2.meite.com/questions/202303/2864228ce0438da.png" />的展开式是()</p><p>答 案:<img src="https://img2.meite.com/questions/202303/2864228d0c480eb.png" /></p><p>解 析:<img src="https://img2.meite.com/questions/202303/2864228d4197eb2.png" /><img src="https://img2.meite.com/questions/202303/2864228d47da120.png" /><img src="https://img2.meite.com/questions/202303/2864228d5101aa0.png" /><img src="https://img2.meite.com/questions/202303/2864228d5bc2a57.png" /><img src="https://img2.meite.com/questions/202303/2864228d65510b6.png" /></p>