ELEMENTS OF PLANE AND SPHERICAL TRIGONOMETRY BY J. W. NICHOLSON, A.M., LL.D. PROFESSOR OF MATHEMATICS, LOUISIANA STATE UNIVERSITY AND New York THE MACMILLAN COMPANY LONDON: MACMILLAN & CO., LTD. 1898 PREFACE THIS book is designed for the use of beginners in the study of Trigonometry. In scope, it presents the common and most essential elements. The author's aim has been to meet the wants of those schools and colleges which, on account of the multiplicity of subjects demanding the attention of the student, or for other causes, have the time or desire to teach only the leading principles of Trigonometry, principles which are essential to the student's progress in higher mathematics, and on which the practical applications of the subject mainly depend. In treatment, the endeavor has been to prepare a wellgraded text-book at once simple, practical, thorough, and as full in details as is consistent with the plan of the work. In deducing and exemplifying principles the author has kept steadily in view the mental training of the student, as well as his advancement in the art of trigonometric computations. Several new features will be found, notably the "Trigonometric Circle" (Art. 23), and the introduction of the terms opposite, adjacent, and like functions (Arts. 18, 20, 25), which it is thought will serve to crystallize the student's ideas of the functions and their relations. A few of the answers to examples and problems are withheld from each exercise. It is thought that the omissions may make the student more attentive to the principles upon which the solutions are based, and the checks by which the results are verified. The answers to the required angles are usually |