  
     h        f0            f2       f2-f0/2h  h^2*exp(h-1)/6 |Actual Error|   
 
    1.        1.          0.135335  - 0.432332    0.166667    0.064453  
    0.2       0.449329    0.301194  - 0.370337    0.002996    0.002457  
    0.1       0.406570    0.332871  - 0.368493    0.000678    0.000613  
    0.02      0.375311    0.360595  - 0.367904    0.000025    0.000025  
    0.01      0.371577    0.364219  - 0.367886    0.000006    0.000006  
    0.002     0.368616    0.367144  - 0.367880    2.46D-07    2.45D-07  
    0.001     0.368248    0.367512  - 0.367880    6.14D-08    6.13D-08  
    0.0002    0.367953    0.367806  - 0.367879    2.45D-09    2.45D-09  
 
 truncation error does not exceed h^2*exp(h-1)/6   