What is the derivative of f(x) = 9x^4 + 3x + -4?
- A. 36x^4 + 3
- B. 9x^3 + 3
- C. 36x^3
- D. 36x^3 + 3 ✓
Correct answer
D. 36x^3 + 3
Explanation
Using the power rule, the derivative of 9x^4 is 36x^3, the derivative of 3x is 3, and the derivative of the constant -4 is 0. So f'(x) = 36x^3 + 3.