The discussion revolves around finding a suitable high school trigonometry course for intermediate learners. Participants recommend various resources, including a specific online textbook and standard trigonometry books used in US remedial college courses. Suggestions emphasize the importance of working through exercises to solidify understanding. One participant highlights the value of connecting with supportive communities for motivation and resources. Additionally, they mention the affordability and clarity of Axler's "Pre-Calculus in a Nutshell" as a potential resource, while seeking clarification on what "deep" learning entails in the context of trigonometry.