The integral value of n for which limx→0cos2x−cosx−ex cos x+ex−x32xn is finite and non zero is

Given limx→0cos2x−cosx−ex cos x+ex−x32xn =limx→0(cosx−1)(cos x−ex)−x32xn=limx→01−x22!+x44!−x66!+....−1xn×1−x22!+x44!−...−1+x+x22!+x33!−...−x32xn limx→0−x22!+x44!−x66!....−x−x2−x33!−2x55!−....−x32xn limx→0x32+x42+x512−x524+.0..−x32xn = non zero if n=4