Jesus S. answered 02/26/23
Patient, Knowledgeable, and Experienced Northwestern Math Tutor
Integrate f'''(x) to get f'(x) = 6x4 - 6x3 + 5x2 + C, where C is a constant.
Integrate f'(x) to get f(x) = (6/5)x5 - (3/2)x4 + (5/3)x3 + Cx + D, where D is a constant.
To check that this works, take the derivative of f(x) to get f'(x) = 6x4 - 6x3 + 5x2 + C, and then take the derivative of f'(x) to get f''(x) = 24x3 - 18x2 + 10x, as desired.
So f(x) = (6/5)x5 - (3/2)x4 + (5/3)x3 + Cx + D