Chapter 5.1, Problem 56E

To determine

To approximate: The area of the region bounded by the function $f\left(x\right)=3x^2+1$ and the $x$-axis over the interval $\left[-1,1\right]$ with $n=10,30,60,80$ subintervals by using the right Riemann sum and make a conjecture about the limit of Riemann sum as $n\to \infty$.