Two waves \({y_1} = {A_1}\sin \left( {\omega t - {\gamma _1}} \right)\), \({y_2} = {A_2}\sin \left( {\omega t - {\gamma _2}} \right)\)
Superimpose to form a resultant wave whose amplitude is1
\(\sqrt {A_1^2 + A_2^2 + 2A_1^2A_2^2\cos \left( {{\gamma _1} - {\gamma _2}} \right)} \)
2
\(\sqrt {A_1^2 + A_2^2 + 2{A_1}{A_2}\cos \left( {{\gamma _1} - {\gamma _2}} \right)} \)
3
\(\sqrt {A_1^2 + A_2^2 + 2A_1^2A_2^2\sin \left( {{\gamma _1} - {\gamma _2}} \right)}\)
4
\(\sqrt {A_1^2 + A_2^2 + 2{A_1}{A_2}\sin \left( {{\gamma _1} - {\gamma _2}} \right)} \)