设A=<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/bc546fc03fdb4ba3b7e6b144b6371d7f.png" />，B=Р(Р(A)) 下列（ ）表达式不成立。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/6e615703da60435893f9e9a9273e12e5.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/64c831067d054e71a6c76f43849d450d.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/72023a5250e44c12b98923044194f13d.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/c48e039a739c4502830eee7ae0ac1678.png" />

理想低通滤波器的传输函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/980b5b2a8d7044b697bc516003ea3acb.png" >是()。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/9a82e2e4ff27470da538512097ee6438.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/c079877bd52d471db3cd6e163f62adbb.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/52aa9898f12641d797c40e4d118bd733.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/a7815d7407f34172aeef470a6adc5f47.png" >

单边拉普拉斯变换<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/423a53f9b3bf40989454133dbce2d262.png" >的原函数等于（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/301dd2111ac64b0e8217cba94ba1a1ab.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/9772eee6eab34c208eba55009d00041b.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/42bfb5f864e34b5ca02a2a1cc9d9c71b.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/659eef6ba24b490191772fe51bab3c9a.png" >

为求方程<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/ce3ea4db5573483a89d1d732d75e1036.png" >在<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/31ea0f26a7064e83856e0c3a268aa9c5.png" >附近的根，则使得迭代格式<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/2cb16d8f43544cca8adc73fc7dce0dff.png" >一定局部收敛的迭代函数为() A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/c52ae5e1d8ca4c51ac71ad740e0bb231.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/54a5d832d2544db7905c50c2c7287f09.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/cdecd203bf8049c5b3faccb7e68a42aa.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/4a5e9a33f10e4d489df882c59db1d545.png" >

已知Z变换Z<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/94487389db974f98b2d38b947ec20d83.png" >，收敛域<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/56b4868c286b4b48a8cec67f9f766670.png" >，则逆变换x（n）为()。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/547656863c8b459da97c366d9321ef13.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/d3572493bf964e2d92fde49d59b632af.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/c4aacba69e0445b0ad4db797b3c86d53.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/b9af7d9dccb3446595a3a587492eb92a.png" >

理想不失真传输系统的传输函数H（jω）是()。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/c53311dbea924826a56276a9472741b1.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/4f089e5988004320950aab7179fb9c28.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/2245b8eb25204e8e966be03821487380.png" >（<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/14618be7a9474fa09351a25e922eb774.png" >为常数） D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/9cba3ab48faa4d8980c79f62bb1f3da4.png" ><img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/64f67bce595243aaa13ded6089b431b1.png" >

下列系统中线性时不变系统是（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/4b45f35cbb8b49eea328e0f1af3a3101.png" >（<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/3f1f37fe4ba54c4fb69d1be115a88f2d.png" >为常数） B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/481b4d4b98e24b94a2eaa9ec011e0186.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/f0f925fadec648b4b7c35161be6f3a3d.png" >（<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/c10b602726304747bf5fe38a760da1ae.png" >为常数） D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/62c5dee47e9045cca90a53856dc04845.png" >

已知主视图和俯视图，下面左视图画法正确的有（ ）<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/2bcab5bbb4024d99b27781c7c286d861.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/c740df10c8d64a5c9f269c0808cfba30.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/d19031d8c17543f699d8827fa6ac1249.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/1780a38439af44618170b420943a6b6d.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/8b29c3cc4c2e4f3e919c5f22d4ac96f1.png" />

已知主视图和俯视图，下面左视图画法正确的有（ ）<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/0e67a6814bf3453d8a2560ad2803175b.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/9cbbab2efe124ef98699ab70b405efa7.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/43768386d66b41419559fe5bf0fb308d.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/3880af04e89d468c8c94acccd953d9c7.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/d4f57df49926458fba76fe114e40f01c.png" />

已知信号<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/82c317e53c6941b59567bc236a6ec9ba.png" >，则奈奎斯特取样频率fs为()。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/7f3cd88d635b4fe0871233447ea5494b.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/53752d34e4c64504bc111e280262e228.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/50d5151b1d3f406185372b2ac9f19f93.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/ad47ea06d5aa4270a8e0089425f0bf6d.png" >