The second derivative of a function $f$ is computed using the fourth-order Central Divided Difference method with a step length $h$.
The CORRECT expression for the second derivative is
- $\frac{1}{12 h^{2}}\left[-f_{i+2}+16 f_{i+1}-30 f_{i}+16 f_{i-1}-f_{i-2}\right]$
- $\frac{1}{12 h^{2}}\left[f_{i+2}+16 f_{i+1}-30 f_{i}+16 f_{i-1}-f_{i-2}\right]$
- $\frac{1}{12 h^{2}}\left[-f_{i+2}+16 f_{i+1}-30 f_{i}+16 f_{i-1}+f_{i-2}\right]$
- $\frac{1}{12 h^{2}}\left[-f_{i+2}-16 f_{i+1}+30 f_{i}-16 f_{i-1}-f_{i-2}\right]$