This is a more advanced site than we need for the introduction in this book, but check out the following discussion of area under a curve:
https://www.intmath.com/integration/3-area-under-curve.php
This is a more advanced site than we need for the introduction in this book, but check out the following discussion of area under a curve:
https://www.intmath.com/integration/3-area-under-curve.php