help please organized your solution (do not cursive)

3.39.) Under certain conditions, the current I(t) measured in amperes at time t in an electrical circuit is given by I(t) = I, [sin(ot + 0) cos o + cos (at + 0) sin $]. Express I (t) as a single sine function of the form given in (7). [Hint: Review the sum formula: sin x, cos x2 + cos x, sin x2.]