The motion of a particle is given by x = A sin ωt + B cos ωt. The motion of the particle is
As x given in the question satisfies the simple harmonic motion equation
∴ the above equation in question is a simple harmonic motion.
And can be represented as
Where , δ is the phase difference and .
In which can also be represented as,
∴ δ can be written as
Hence, amplitude becomes.