是罍。https://image.zhihuishu.com/zhs/onlin...a3e9b028e3c12a23.png
举一反三
- 是罍。https://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/c22b1219723f4bb6a3e9b028e3c12a23.png
- Matlab命令A=magic(3)创建一个3阶魔方矩阵，求A的逆矩阵用（ ）. A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/4a74527efd484dd8b5c75050a75c1641.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/0bad2e09e7384b81890448a707e1f260.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/6164767c2a40423d938b2b87dd52cd3d.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/5812422f3e1a4a7185ba0e187c5d21df.png" />
- 中缀表达式23+((12*3-2)/4+34*5/7)+108/9对应的后缀表达式为（ ）。 A: 23 12 + 3 * 2 – 4 / 34 5 * 7 / + 108 9 / + B: 23 12 3 * 2 4 – / 34 5 * 7 / + + 108 9 / + C: 23 12 3 * 2 – 4 / 34 5 * 7 / + 108 9 / + + D: 23 12 3 * 2 – 4 / 34 5 * 7 / + + 108 9 / +
- Matlab命令A=magic(3)创建一个3阶魔方矩阵，求A的特征值的绝对值的最小值用（ ）. A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/d605a0a8e560440081a209fc0da04637.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/e36ed713fb2e481ab69ecd158317c17e.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/6cd6fb595e6d45fd962a01d8b6ac10f5.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/64c2c88e6099475dbacd7e6d12841129.png" />
- 某人举步上楼梯，每步跨1个台阶或2个台阶，设上n个台阶的不同方式数为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/62999550ec1547439283cd9872427fdc.png" />，则( ). A: 初始条件为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/e5083263b09044c1b6e95baed3ef628c.png" />=1，<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/07aa95ceccda433f8e9432a186fae005.png" />= 2, 递归关系为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/ad0a958e510040be8f4253d0526d7ce5.png" />(n≥3). B: 初始条件为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/d5cc33a9d0714d3fbba386ccff5f8aaa.png" />=1，<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/34a42e4a62ea448db919ffa607f5de44.png" />= 1, 递归关系为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/c3dc9b741afa4ae68983bc1d5db5e065.png" />(n≥3). C: 初始条件为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/405917811f9845e1915af00c9fa30c79.png" />=1，<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/ccd3e7a79651413b8cd22dbf5cd05ac8.png" />=1, 递归关系为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/0acc9967cdab4f31a918b5fc8fe38608.png" />(n≥3). D: 初始条件为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/245baeee86b943e4bd7f1c39803b142c.png" />=1，<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/a06359868bb1457e81ab7e102d212630.png" />= 2, 递归关系为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202010/0aee376a7bfa44da9f431ecb21e6c787.png" />(n≥3).