Two simple harmonic motions are given by
`y_(1)=A_(1)sinomegat andy_(2)=A_(2)sin(omegat+phi)` are acting on the particles in the same direction .The resultant motion is S.H.M., its amplitude is
A. `sqrt(A_(1)^(2)+A_(2)^(2)+2A_(1)A_(2)cosphi)`
B. `sqrt(A_(1)^(2)+A_(2)^(2)-2A_(1)A_(2)cosphi)`
C. `A_(1)^(2)+A_(2)^(2)-2A_(1)A_(2)cosphi`
D. `A_(1)^(2)+A_(2)^(2)+2A_(1)A_(2)cosphi`
