周期函数的傅里叶级数展开式为（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/1acf375a576742098a458e5fefb60da0.png
举一反三
- 函数 是周期函数，周期为.（ ）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201809/972d5706721546c09a9c63c0dbbc07e0.png
- 设函数 是以 为周期的周期函数，它在 上的 表达式为 将它展开成傅里叶级数，该系数 正确吗？https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/f33a86428b7f41df9e3c5ee032219449.png
- 信号波形如图所示，求其三角形式傅里叶级数。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/762886bac78f4048a5f95e16046ee6ac.png
- 拉普拉斯（Laplace）方程的表达式为（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/26731bcad75f41389448b29292940653.jpg" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/40e7e55a72ee44f59b45d20c84ebe3a6.jpg" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/c65a79ea4d754174b99f34020d6e1735.jpg" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/139e8d3dc37941549e7b6b1731243172.jpg" />
- 平面一维稳定渗流的压力分布公式为（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/d08348f3b84f442d87994311dc13686b.jpg" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/2df214c86c5e4103897ba81ce2c6cd98.jpg" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/cc98e4a778cc463c965ac8115e028f86.jpg" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/bc82177c19d44acfa1b365c3d66ed0a4.jpg" />