Here phase difference =$\frac{\pi }{2}$
$\therefore $ The resultant amplitude
= $\sqrt {{{\left( {\frac{1}{{\sqrt a }}} \right)}^2} + {{\left( {\frac{1}{{\sqrt b }}} \right)}^2}} = \sqrt {\frac{1}{a} + \frac{1}{b}} = \sqrt {\frac{{a + b}}{{ab}}} $
${x_1} = a\sin (\omega \,t + {\phi _1})$, ${x_2} = a\sin \,(\omega \,t + {\phi _2})$
If in the resultant wave the frequency and amplitude remain equal to those of superimposing waves. Then phase difference between them is
