- Find the most general antiderivative of the function. (Check your answer by differentiation. Use C for the constant of the antiderivative.)

a) f (x) = 8x^{9}− 2x^{6}+ 15x^{3}F(x) =

b) f (x) = (x + 3) (4x − 6) F(x) = - Find f. (Use C for the constant of the first antiderivative and D for the constant of the second antiderivative.)

f ′′(x) = 6x + sin (x), f (x) = .