设L为圆周[img=89x26]1803d35ae29734a.png[/img],则[img=126x60]1803d35aee561b6.png[/img]
A: [img=20x18]1803d35af65421a.png[/img]
B: [img=34x20]1803d35afed861f.png[/img]
C: [img=20x18]1803d35b0736863.png[/img]
D: [img=20x18]1803d35b0f3d12a.png[/img]
A: [img=20x18]1803d35af65421a.png[/img]
B: [img=34x20]1803d35afed861f.png[/img]
C: [img=20x18]1803d35b0736863.png[/img]
D: [img=20x18]1803d35b0f3d12a.png[/img]
举一反三
- 设L为圆周[img=89x26]1803d35d037e4fc.png[/img],则[img=168x60]1803d35d0efd093.png[/img] A: [img=20x18]1803d35d187b5cf.png[/img] B: [img=34x20]1803d35d20693ed.png[/img] C: [img=20x18]1803d35d27dfa31.png[/img] D: [img=20x18]1803d35d30a8b43.png[/img]
- 设L为取正向的圆周[img=89x26]1803d347adb69bd.png[/img]，则曲线积分[img=294x48]1803d347b7f3e9d.png[/img] A: [img=34x20]1803d347c08bd47.png[/img] B: [img=20x18]1803d347c8e9b5d.png[/img] C: [img=34x20]1803d347d14b81c.png[/img] D: [img=20x18]1803d347da71620.png[/img]
- 设L为取正向的圆周[img=89x26]1803d3401adc9f7.png[/img]，则曲线积分[img=294x48]1803d3402656417.png[/img] A: [img=34x20]1803d340309e7a2.png[/img] B: [img=20x18]1803d340395584d.png[/img] C: [img=34x20]1803d340415e488.png[/img] D: [img=20x18]1803d34049e4a02.png[/img]
- X为随机变量，E(X)=-1，D(X)=3，则E(3[img=24x22]1803da40b5dbfd6.png[/img]+20)=( ) A: 18 B: 9 C: 30 D: 32
- X为随机变量，E(X)=-1，D(X)=3，则E(3[img=24x22]1803da40ac7a8ce.png[/img]+20)=( ) A: 18 B: 9 C: 30 D: 32