Consider the periodic function f(t) = cos (t/ 2 3/ 4) 2 sin (t/ )2 that arises from two out-of-phase inputs.

a) Rearrange this expression for f(t) into an equivalent form f(t) = A sin (t/ 2) + B cos (t/ 2)

b) Identify the period of the function f(t), providing brief reasons for your answer.

c) Determine the amplitude C and the principal angle when f(t) is written as a cosine function in phase angle form f(t) = C cos (t/ 2 + ) . Justify your answers carefully