代数方程在实数集范围内有()个解。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/67f02762375242aaa2991ac47053b7d4.png
举一反三
- 理想运算放大器的主要特征为 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/8ec216c374814f48ad60b00627bee3d6.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/b36e9dfc39a748b1b652e9b3c1a762ed.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/2a93dfdbeb804030ac0da51eed08943e.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/a01ee7baba84489f886c43cc5d5c5169.png" />
- 负反馈系统的开环传递函数为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/a7ed7837bacb42a0bc3a3b685f1f59ca.png" />，若要绘制参数<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/20abe260498a4ba4ac78f48ef331ea76.png" />的根轨迹，其等效开环传递函数应该是（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/3fd90fdfd9534f81b6f4b6052f381f27.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/c39a9d3fb81b47bead514a12c4ad843d.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/916d03716ed144c58426442cc710f9fa.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/2f2d63241a46476a9ece1e3ccd8e96e5.png" />
- 正六边形的尺寸标注正确的是（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/51b59d5c82e7484292873ae39ff944fd.jpg"> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/dad8740e848246faae714a02eb3e79f6.jpg"> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/5d7eebc6e83247cd921d440438341839.jpg"> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/ef49ee3205524fb5b9fc6c643aef5bad.jpg">
- 以下属于典型二阶欠阻尼系统的是。（ ） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/17af3a9e051c466584b8cec615049edd.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/6c04a26728e34a868e6efa4d4043d018.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/7c45b6ba62234c5e978202c49dd4b455.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/8f6cf90035484380beadadba728063ac.png" />
- 逻辑函数F (A,B,C)=Σ m (0，1，4，6)的最简与非-与非式为（ ） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/6677dfd1ca0a4255871fff8d24c1bfe1.png"/> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/5556e6fba4d849c988d994a19156d44a.png"/> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/6f296abd190d40b19f2f737f02c7adca.png"/> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/b2bf2478b09b4e6ab818d71adb4a8715.png"/>