For travelling wave \(y\) should be linear function of \(x\) and \(t\) and they must exist as \((x \pm v t)\)
\(y = A \sin (15 x-2 t) \rightarrow\) linear function in \(x\) and \(t.\)
$y = a\sin (kx + \omega t)$ ......$(1)$
$y = a\sin (\omega t - kx)$ .....$(2)$
$y = a\cos (kx + \omega t)$ .....$(3)$
$y = a\cos (\omega t - kx)$ .....$(4)$
में व्यतिकरण घटना उपयुक्त प्रतिबन्धों के अन्तर्गत होती है जब