Chapter 5.4, Problem 32ES

Use a calculating utility with summation capabilities or a CAS to obtain an approximate value for the area between the curve $y=f\left(x\right)$ and the specified interval with $n=10,20,$ and $50$ subintervals using the $\left(a\right)$ left endpoint, $\left(b\right)$ midpoint, and $\left(c\right)$ right endpoint approximations.

$f\left(x\right)=1/x^2;\left[1,3\right]$