2024年成考高起点《数学(理)》每日一练试题01月31日
<p class="introTit">单选题</p><p>1、<img border="0" style="width: 58px; height: 37px;" src="https://img2.meite.com/zzpuce/2023-04/643679c8eed3a35616.jpeg">( )</p><ul><li>A:-2</li><li>B:<img border="0" style="width: 24px; height: 37px;" src="https://img2.meite.com/zzpuce/2023-04/643679c9008af39045.jpeg"></li><li>C:<img border="0" style="width: 14px; height: 37px;" src="https://img2.meite.com/zzpuce/2023-04/643679c90917e56279.jpeg"></li><li>D:2</li></ul><p>答 案:C</p><p>2、设双曲线<img src="https://img2.meite.com/questions/202303/2864229bffc903a.png" />的渐近线的斜率为k,则|k|=()
</p><ul><li>A:<img src='https://img2.meite.com/questions/202303/2864229c1452370.png' /></li><li>B:<img src='https://img2.meite.com/questions/202303/2864229c18b1b1c.png' /></li><li>C:<img src='https://img2.meite.com/questions/202303/2864229c22758e7.png' /></li><li>D:<img src='https://img2.meite.com/questions/202303/2864229c1da4817.png' /></li></ul><p>答 案:D</p><p>解 析:双曲线渐近线的斜率为k<img src="https://img2.meite.com/questions/202303/2864229c7d57118.png" />故本题中k<img src="https://img2.meite.com/questions/202303/2864229c8e41a4f.png" /></p><p>3、下列函数中,为减函数的是()</p><ul><li>A:<img src='https://img2.meite.com/questions/202303/1564116457c8a2d.png' /></li><li>B:<img src='https://img2.meite.com/questions/202303/156411645ea88b7.png' /></li><li>C:<img src='https://img2.meite.com/questions/202303/1564116464062a5.png' /></li><li>D:<img src='https://img2.meite.com/questions/202303/1564116467a737e.png' /></li></ul><p>答 案:C</p><p>解 析:由对数函数的性质可知,当底数大于0小于1时,在定义域内,对数函数为减函数.</p><p>4、某类灯泡使用时数在1000小时以上的概率为0.2,三个灯泡在使用1000小时以后最多只有一个坏的概率为()</p><ul><li>A:0.008</li><li>B:0.104</li><li>C:0.096</li><li>D:1</li></ul><p>答 案:B</p><p>解 析:已知灯泡使用1000小时后好的概率为0.2,坏的概率为1-0.2=0.8,则三个灯泡使用1000小时以后,可分别求得: P(没有坏的)<img src="https://img2.meite.com/questions/202303/2864228c0d3040c.png" />
P(一个坏的)<img src="https://img2.meite.com/questions/202303/2864228c17bc440.png" />故最多只有一个坏的概率为:0.008+0.096=0.104.
</p><p class="introTit">主观题</p><p>1、在△ABC中,B=120°,BC=4,△ABC的面积为<img src="https://img2.meite.com/questions/202303/15641165ec55404.png" />,求AC.</p><p>答 案:由△ABC的面积为<img src="https://img2.meite.com/questions/202303/15641165ec55404.png" />得<img src="https://img2.meite.com/questions/202303/1564116bba3c98d.png" />所以AB =4.因此<img src="https://img2.meite.com/questions/202303/1564116be4bebd5.png" />所以<img src="https://img2.meite.com/questions/202303/1564116be967e8f.png" /></p><p>2、在正四棱柱ABCD-A'B'C'D'中,<img src="https://img2.meite.com/questions/202303/2864229a3bc3098.png" />
(Ⅰ)写出向量<img src="https://img2.meite.com/questions/202303/2864229a57ba174.png" />和<img src="https://img2.meite.com/questions/202303/2864229a5e46ac8.png" />关于基底{a,b,c}的分解式;
(Ⅱ)求证:<img src="https://img2.meite.com/questions/202303/2864229a76ba56d.png" />
(Ⅲ)求证:<img src="https://img2.meite.com/questions/202303/2864229a7fdd541.png" />
</p><p>答 案:(Ⅰ)由题意知(如图所示) <img src="https://img2.meite.com/questions/202303/2864229af6b1567.png" />
<img src="https://img2.meite.com/questions/202303/2864229afe90f50.png" />
<img src="https://img2.meite.com/questions/202303/2864229b08314c5.png" />
</p><p>3、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>4、在正四棱柱ABCD-A'B'C'D'中,<img src="https://img2.meite.com/questions/202303/28642255fa50503.png" />
(Ⅰ)写出向量<img src="https://img2.meite.com/questions/202303/286422561b1d145.png" />关于基底{a,b,c}的分解式
(Ⅱ)求证:<img src="https://img2.meite.com/questions/202303/286422563d58cde.png" />
(Ⅲ)求证:<img src="https://img2.meite.com/questions/202303/28642256478aacd.png" />
</p><p>答 案:(Ⅰ)由题意知(如图所示) <img src="https://img2.meite.com/questions/202303/286422566983935.png" />
<img src="https://img2.meite.com/questions/202303/28642256740213a.png" /><img src="https://img2.meite.com/questions/202303/286422567c06c5d.png" />
(Ⅱ)<img src="https://img2.meite.com/questions/202303/2864225695c5fbd.png" /><img src="https://img2.meite.com/questions/202303/286422569cdc533.png" />
(Ⅲ)<img src="https://img2.meite.com/questions/202303/28642256a537b6d.png" />
由已知,a,c是正四棱柱的棱,a,b,c两两垂直
<img src="https://img2.meite.com/questions/202303/28642256d1c4379.png" />
</p><p class="introTit">填空题</p><p>1、长方体的长、宽、高分别为2,3,6,则该长方体的对角线长为()</p><p>答 案:7</p><p>解 析:由题可知长方体的底面的对角线长为<img src="https://img2.meite.com/questions/202303/1564116b1132166.png" />,则在由高、底面对角线、长方体的对角线组成的三角形中,长方体的对角线长为<img src="https://img2.meite.com/questions/202303/1564116b3811959.png" /></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>