Hello, everyone, as shown in the figure below, how to use the tangent L of point A as the y'axis direction, and the direction perpendicular to the y'axis as the x'axis. Establish such a coordinate system to facilitate local analysis.

[DGM]

I don't see that a question has been asked. Maybe this will help.

https://www.mathworks.com/matlabcentral/answers/8626-how-do-i-get-help-on-homework-questions-on-matlab-answers

https://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

This isn't any different than asking your TA or instructor. You should be prepared to demonstrate what efforts you've made to answer your own question before you ever present it to someone else. It's not merely a matter of courtesy or academic integrity; at the most basic level, it communicates where you are in the problem solving process and reduces the amount of time wasted by everyone involved.

[Wesley]

My idea is how to rotate the coordinate system.