आवर्ती विस्थापन `y = A cos omega t +A cos (omegat +(2pi)/3)+A cos (omegat +(4pi)/3)` का परिणाम होगा -

Options

A. `3 A cos omegat`
B. `3A cos(pi//2)`
C. `3A cos pi`
D. इनमे से कोई नहीं

Answer

B

Explanation

` y = A cos omega t + A cos (omega t +(2pi)/3)+A cos (omegat+(4pi)/3)`
` =A cos omegat +A[cos(omegat+(4pi)/3)+cos(omegat+(2pi)/3)]`
`= A cos omegat+A[2 cos(omegat+pi)cos.pi/3]`
` = A cos omegat+A[ -2 cos (omegat+pi)cos.pi/3]`
`= A cos omegat+A[-2 cos omegatxx1/2]=A[cos omegat-cos omegat]`
= 0
` = 3 A cos.pi/2 , " "[ :' cos.pi/2 =0]`