""An Elementary Treatise On The Application Of Trigonometry"" is a book written by John Farrar and published in 1840. The book is a comprehensive guide to trigonometry, which is a branch of mathematics that deals with the relationships between the sides and angles of triangles. The book covers various topics related to trigonometry, including the definitions of trigonometric functions, the use of logarithms in trigonometry, and the application of...