1. 设题4图 (a)所示信号http://img2.ph.126.net/mdupcFxlsOkyvuscItqFIQ==/6608438716887735791.png的频谱http://img2.ph.126.net/-sGhI323Tr0yt1OwHRe20g==/6631437201607930994.png已知，则题4图 (b)所示信号http://img0.ph.126.net/An0Bj4yw02TeJvCw4kT1Qw==/6619515197025592278.png的频谱http://img2.ph.126.net/abbBaDCt2Vct2hhQQmrDAQ==/6631374529445217284.png 为 ( ) http://nos.netease.com/edu-image/46988664AF81F97D896D8324C9BB83F3.bmp?imageView&type=jpeg&thumbnail=520x520&quality=100
举一反三
- 在题30图所示系统中，已知输入信号http://img2.ph.126.net/mdupcFxlsOkyvuscItqFIQ==/6608438716887735791.png的频谱为http://img1.ph.126.net/Qb6wHkNlaXg7sGDatjXkdA==/6630691732724661829.png，输出http://img0.ph.126.net/An0Bj4yw02TeJvCw4kT1Qw==/6619515197025592278.png的频谱为( )http://nos.netease.com/edu-image/B9B387F861095FAB70D131ECC35E522F.bmp?imageView&type=jpeg&thumbnail=520x520&quality=100
- [img src="http://edu-image.nosdn.127.net/08446072FAF419F6F5FB52568347381A.bmp?imageView&type=jpeg&thumbnail=520x520&quality=100"][img src="http://edu-image.nosdn.127.net/950BA54637600A69A19C15A66AC36500.bmp?imageView&type=jpeg&thumbnail=520x520&quality=100"] A: -4 B: +2 C: -1 D: -2
- 图所示机构的自由度是（ ）。[img=197x160]18034e492717e18.jpg[/img] A: n=8, PL=11, Ph=1, F=1 B: n=8, PL=10, Ph=2, F=2 C: n=9, PL=12, Ph=2, F=1 D: n=9, PL=13, Ph=0， F=1
- [img src="http://edu-image.nosdn.127.net/E524966EFC5273037E2615670F2A060E.bmp?imageView&type=jpeg&thumbnail=890x0&quality=100"] A: 1 B: 2 C: 3 D: 4
- 图所示机构的自由度是（ ）。[img=225x225]18034e49029b42b.jpg[/img] A: n=7, PL=10, Ph=0, F=1 B: n=9, PL=12, Ph=2, F=1 C: n=8, PL=11, Ph=1, F=1 D: n=8, PL=11, Ph=0, F=2