Answer:Tap for more steps... By the Sum Rule, the derivative of x 4 + 3 x 2 x 4 + 3 x 2 with respect to x x is d d x [ x 4] + d d x [ 3 x 2] d d x [ x 4] + d d x [ 3 x 2]. Differentiate using the Power Rule which states that d d x [ x n] d d x [ x n] is n x n − 1 n x n - 1 where n = 4 n = 4.