Who is asking: Student
Level: Secondary
Question:
hi
i used excel to find the area under a graph instead of integrating the function the analytical way. These are the different answers i got with different width of the x-values, the smaller the x-increment gets the more precise the area is when compared to the answer obtained the numerical way. I have trouble seeing why the answers i get is getting bigger and bigger and not smaller can someone plz explain?
Area under curve (in area units):
| x-increment | Approximate area |
| 1 | 11.2187436 |
| 0.5 | 11.4302568 |
| 0.3 | 11.5484789 |
| 0.25 | 11.6127904 |
| 0.1 | 11.7361791 |
| 0.05 | 11.7793645 |
| 0.01 | 11.8146327 |
| 0.005 | 11.8190861 |
| 0.001 | 11.8226559 |
| 0.0005 | 11.8231026 |
| 0.0001 | 11.8234600 |
| 0.00005 | 11.8235046 |
Hi,
I don't know what function you are integrating but it looks to me that what you have done is correct. If possible I would add another column to the table. If you can integrate the function and calculate the area analytically to find the actual area then add a column which is the absolute value of the difference between the actual area and the approximate area. The numbers in this column should get smaller.
Penny