I am reading Paul Online Maths Notes for Calculus I. I am reading it on my own. Everything was fine untill I reached Application of Integration section. I am not particularly good at graphing and sketching functions. It is causing me problems in understanding the problem and visualizing the situation.
For example in questions on "Finding area between the curve", I am not able to see which function is upper and which one is lower.
Question: Can someone please advise me on how to improve on skill of graphing and sketching functions. Is there an online resource/textbook from where I can read the various techniques? Where should I start learning/building this skill?
I would be thankful if somebody answers this.
If you are looking at https://tutorial.math.lamar.edu/classes/calci/AreaBetweenCurves.aspx, there are two graphs with two functions shown on each graph.
The first graph has an "upper" function and a "lower" function. In the figure below I have added labels to show which is which.
The second graph as a "left" function and an "right" function as labeled in the figure below.