(1 point) (a) Using a trig identity, write (t) = cos(8t) - 5 sin(8t) using only one cosine function. x(t) = help (formulas) (b) Using a trig identity, write z(t) = (cos(8t)) - 5 sin(8t) using only one cosine function x(t)= help (formulas) (c) Using a trig identity, write (t) =e" (cos(8t) - 5 sin(8t)) using only one cosine function in your answer. x(t) = help (formulas)