7. [-/5 Points] DETAILS LARCALC10 2.3.124. Find the derivative of the function f for n = 1, 2, 3, and 4. f ( x ) = COS X n =1 f'( x ) = n = 2 f'(x) n = 3 f '(x) = n = 4 f '( x) = Use the results to write a general rule for f (x) in terms of n. f ' ( x ) =