TRIGONOMETRY BY ALFRED MONROE KENYON PROFESSOR OF MATHEMATICS, PURDUE UNIVERSITY AND LOUIS INGOLD ASSISTANT PROFESSOR OF MATHEMATICS, THE UNIVERSITY OF MISSOURI EDITED BY EARLE RAYMOND HEDRICK New York THE MACMILLAN COMPANY 1913 All rights reserved Set up and electrotyped. Published May, 1913. Reprinted Norwood Press PREFACE IN Trigonometry, as elsewhere, a motive for the study of each topic is necessary to secure the effective attention of the student. The knowledge required for the actual solution of triangles - the one motive common to all texts on Trigonometry — is only a fraction of the traditional course, even when the refinements necessary for logarithmic solution are included. Thus, the addition formulas, as such, the solution of trigonometric equations, and all reference to angles larger than 180°, are unnecessary for any process of solution of plane triangles. In order to share with the student the teacher's knowledge that these other topics are of real importance, other practical problems of an elementary nature are used to introduce them. Thus, composition and resolution of forces is made an introduction to the study of large angles, and is used to illustrate the meaning of the addition formulas. Large angles are also used in problems on rotation and angular speed. Radian measure is shown to be useful in problems on rotation and on mensuration. Topics for which no wide application exists that is within the student's present grasp - such as De Moivre's theorem and infinite series are omitted. Thus the book contains a minimum of purely theoretical matter. Its entire organization is intended to give a clear view of the meaning and the immediate usefulness of Trigonometry. The proofs, however, are in a form that will not require essential revision in the courses that follow. The solution of triangles remains the principal motive. As such, it is attacked immediately and no diversion is indulged in until this problem has been completely solved. A sharp distinction is made between the fundamental principles of solu 419460 |