设A,B都是n阶方阵，则下列结论正确的是（ ）
A: 若AB是奇异矩阵，则A和B都是奇异矩阵
B: 若AB是可逆矩阵，则A和B都是可逆矩阵
C: 若
且 
，则
D: 若A和B都是对称矩阵，则AB也是对称矩阵
A: 若AB是奇异矩阵，则A和B都是奇异矩阵
B: 若AB是可逆矩阵，则A和B都是可逆矩阵
C: 若
且 ，则D: 若A和B都是对称矩阵，则AB也是对称矩阵
举一反三
- 奇数阶反对称矩阵的行列式等于0. （ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/21922138f8d2462b8d2d057e7ec53439.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/52d68283c0dc47d1afc20cf608bf90f7.png" />
- 通过点<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/a13927df1bf542dfa036a32b10364f69.png" />的拉格朗日插值基函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/65695a42c7a14b649b6aa4fb68f7e499.png" />满足( ) A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/99af333f3e934ef6a75022ee1e728b53.png" />＝1，<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/7769611ac5cd4c93975be7c41a49ae71.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/99af333f3e934ef6a75022ee1e728b53.png" />＝1，<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/7769611ac5cd4c93975be7c41a49ae71.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/99af333f3e934ef6a75022ee1e728b53.png" />＝0，<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/7769611ac5cd4c93975be7c41a49ae71.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/99af333f3e934ef6a75022ee1e728b53.png" />=0，<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/f80e8e400f3f4916bcaf6b5fde757f16.png" />
- 设系统的初始条件为零，其微分方程为：<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/9c4c212cc1594dd19dcfc992512ba0e1.png" />，则_____。() A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/3f8dd968db6e49f5a261281ea5f038bc.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/a73ceb98e53043eb9817c3014694d0b3.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/cfbf541fa5504f819df5429a3c181a0d.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/404ca95df5b34ade860d159893fbb0e2.png" />
- <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/48fc4686323b4fc2aed9a5ded068e010.png" />则MnS在盐酸中溶解的平衡常数为（ )。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/92fc7a394f754ea59f5812ddedfa9ca1.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/4f1e00c110584145843649c7c0f0fa55.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/ca9777100e5d4abeaa282239afdb5ee0.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/aacd92054a5745feb6f3c98233158b95.png" />
- 下列结论错误的是（） A: 如果函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/18a10ebd75f54d9ba2de6c77fb99c56d.png">在点<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/3e7d8d0d9aba463faf8ba22335557789.png">处连续，则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/18a10ebd75f54d9ba2de6c77fb99c56d.png">在点<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/3e7d8d0d9aba463faf8ba22335557789.png">处可导 B: 如果函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/18a10ebd75f54d9ba2de6c77fb99c56d.png">在点<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/3e7d8d0d9aba463faf8ba22335557789.png">处不连续，则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/18a10ebd75f54d9ba2de6c77fb99c56d.png">在点<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/3e7d8d0d9aba463faf8ba22335557789.png">处不可导 C: 如果函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/18a10ebd75f54d9ba2de6c77fb99c56d.png">在点<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/3e7d8d0d9aba463faf8ba22335557789.png">处可导，则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/18a10ebd75f54d9ba2de6c77fb99c56d.png">在点<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/3e7d8d0d9aba463faf8ba22335557789.png">处连续 D: 如果函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/18a10ebd75f54d9ba2de6c77fb99c56d.png">在点<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/3e7d8d0d9aba463faf8ba22335557789.png">处不可导，则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/18a10ebd75f54d9ba2de6c77fb99c56d.png">在点<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/3e7d8d0d9aba463faf8ba22335557789.png">处也可能连续