Numerical Methods: Compute Right, Left, Trap, Mid & Compare to Exact Value of Integral | (Ali BA)

To find left sum:
1- You need to find the width of each sub-devision (rectangles), delta x = (b-a)/n .
Where
a: start of the interval
b: end of the interval
n: number of sub-divisions
2- For the length of the rectangles, you want to start from the left point, that is from the start of the interval and then increase by delta x. 3- To find the left sum, you find the area of the rectangles (length by the width) and add them together.

You repeat the same steps for the right sum, but for 2, you start from the right point, that is from the ends point.

Also, this is similar steps to Mid, but you start by the middle point for step 2.

To find which one is closer to the exact value of the integral, you find the error. That is Actual value minus Estimation value. In our case, the lowest value of error with the estimation Mid(2).

If you have any questions or suggestions, let me know in the comments below.

Material in this video is taken from Calculus: Single Variable, 6th Edition by (Hallet, McCallum, Gleason, et al.)