1 The motion is oscillating but not SHM
2 The motion is SHM with amplitude \(a + b\)
3 The motion is SHM with amplitude \(a^{2}+b^{2}\)
4 The motion is SHM with amplitude \(\sqrt{a^{2}+b^{2}}\)
Explanation:
Given, \(y=a \sin \omega t+b \cos \omega t\)
Let \(a = A\cos \theta \,\,{\rm{and}}\,\,b = A\sin \theta \,\,\,\,\,\,\,\,\,\,(1)\)
then \(y=A \cos \theta \sin \omega t+A \sin \theta \cos \omega t\)
\(y=A \sin (\omega t+\theta)\)
Which is in the form of SHM
From Eq. (1)
\({a^2} + {b^2} = {A^2}{\cos ^2}\theta + {A^2}{\sin ^2}\theta \)
\( \Rightarrow A = \sqrt {{a^2} + {b^2}} \)