The equation `y=Acos^(2)[2pint-2pi(x)/(lamda)]` represents a wave with

Options

A. amplitude A/2, frequency 2n and wavelength `lamda`
B. amplitude A/2, frequency 2n and wavelength `lamda//2`
C. amplitude A, frequency n and wavelength `lamda`
D. amplitude A, frequency 2n and wavelength `2lamda`

Answer

B

Explanation

`y=Acos^(2)[2pint-2pi(x)/(lamda)]`
`=A[(1+cos2(2pint-2pix//lamda))/(2)]`
`=(A)/(2)+(A)/(2)cos(4pint-4pi(x)/(lamda))`
Comparing with standard wave equations we get,
amplitude`=A//2`, frequency=2n
wavelength `=lamda//2`.