I am a first year engineer student here in my country we have a first preparatory year so I was looking for a deep understanding book for trigonometry
Because I have always had a hard time with this hyperbolic and cosecant and inverse functions thing
So if any one could recommend a set of books in order to read to really understand and have a deep look at this subject would be great
You can't go wrong with any of Gelfand's books. I would recommend his book "Trigonometry."
https://www.amazon.com/Trigonometry-I-M-Gelfand/dp/0817639144