How to solve a 2nd derivative problem (business calculus) By Songoku23 Nov 16, 2025 Find the 2nd derivative f''(x) f'(x)=9 goes to f''(x)=0; The derivative of 9 (which is a constant) is 0 Nov 16, 2025 Start with the given function f(x)=9x+2 Nov 16, 2025 Find the 1st derivative f'(x) f(x)=9x+2 goes to f'(x)=9; The derivative of 9x is 9 and 2 is a constant which is 0 Nov 16, 2025 The final result f"(x)=0