1) ∫(27e9x+e12x)1/3dx is equal to A) (1/4)(27+e3x)1/3+C B) (1/4)(27+e3x)2/3+C C) (1/3)(27+e3x)4/3+C D) (1/4)(27+e3x)4/3+C Answer: Option DExplanation:Let I = ∫(27e9x+e12x)1/3dx = ∫e3x(27+e3x)1/3dx Put 27+e3x = t 3e3xdx = dt I = 13∫t1/3dt = 13t4/34/3+C = (1/4)(27+e3x)4/3+C