Sound wave is travelling in a medium. If equation of a displacement wave in the

Dear Student,
Answer to your question is given below:
Assumption: Since the question is unclear, i have assumed that the question is about the equation of the wave.
When sound wave is travelling in a medium, the displacement of the medium in a sound wave is given by the equation,

$y = A \mathrm{co}s (ax+bt)$

where, a and b are positive constants and we assume that the wave is travelling in the positive x-direction.

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Regards,