Find the indefinite integral of each of the following by using [ f'(x)[f(x)"]dx =[ [f(x)]^n+1 / n+1] + c, where n #1 (a) e^x (3 - e^x)^4 dx (b) 3e^2x √(1 + e²x) dx (c) 3e^-2x / (1 + e^-2x)^3 dx (d) 4 cos 2x sin³ 2x dx (e) sec² 3x tan³ 3x dx (f) 2+tan ² x / cos² x dx