两相干平面简谐波，振幅都是A，沿同一方向传播，相位差为[img=11x39]1802da4eee0da19.png[/img]，则合成波的振幅是
A: [img=23x19]1802da4ef6744aa.png[/img]
B: [img=39x26]1802da4eff4d8c0.png[/img]
C: [img=14x19]1802da4f077108e.png[/img]
D: [img=23x19]1802da4f0f97f36.png[/img]
A: [img=23x19]1802da4ef6744aa.png[/img]
B: [img=39x26]1802da4eff4d8c0.png[/img]
C: [img=14x19]1802da4f077108e.png[/img]
D: [img=23x19]1802da4f0f97f36.png[/img]
举一反三
- 设正态分布N(0, 4)的分布函数为F(x)，则F’(x) = ( ). A: [img=73x63]1802f2c47707b95.png[/img] B: [img=86x65]1802f2c47feb07a.png[/img] C: [img=75x58]1802f2c4884644b.png[/img] D: [img=87x58]1802f2c48fffbbf.png[/img]
- 设正态分布N(0, 4)的分布函数为F(x)，则F’(x) = ( ). A: [img=73x63]1802f2a8aba67a6.png[/img] B: [img=86x65]1802f2a8b46de33.png[/img] C: [img=75x58]1802f2a8bcdd988.png[/img] D: [img=87x58]1802f2a8c497bb0.png[/img]
- 设正态分布N(0, 4)的分布函数为F(x)，则F’(x) = ( ). A: [img=73x63]18031e92d8d1247.png[/img] B: [img=86x65]18031e92e1612dc.png[/img] C: [img=75x58]18031e92e9c3836.png[/img] D: [img=87x58]18031e92f20200d.png[/img]
- 设f(x)为连续函数，且 [img=217x49]18034a50d8b1b92.png[/img] 则[img=70x25]18034a50e196c62.png[/img] A: 5 B: 4 C: 0 D: -5
- 若f(x)+f(-x)=0, 则[img=95x39]17da608af452d96.jpg[/img]. 若f(x)=f(-x), 则 [img=170x38]17da60541207426.jpg[/img]