Here you can download Plane Trigonometry by S L Loney PDF. This book covers more than the syllabus of JEE. It has great quality concepts and subjective problems.
I recommend this book as a reference book along with your coaching materials like DPP’s, notes. If you are studying own you can download coaching material for maths on this website itself for free.
For solutions for this book click here
(or) Buy the original hard copy books from amazon to support the author and for easy preparation. Since this book is very huge in terms of pages it is reasonable to consider purchasing one rather than reading from your device which strains your eyes. Also, I recommend Arihant plane trigonometry by S L Loney book for JEE preparation since that book strictly stuck to JEE syllabus hence you can prepare without wasting your time on markings. And that book is also very cheap ( just around 100 rupees in the market ).