Estimating the area under a curve using random points in R

Even though this post is not the first one on this blog, the code I used to estimate the area under the curve x^2 and posted below is one of my first attempts to code something "complicated" with R. It has been more than 5 months since I wrote it, it does look a bit clunky now. Indeed. However I believe it is fun to keep an eye on our own written code and see how it has evolved. Even though the code is lengthy, the final result looks nice.

 

Here is the result you should get: