MACMILLAN AND CO., LIMITED LONDON BOMBAY CALCUTTA THE MACMILLAN COMPANY NEW YORK. BOSTON. CHICAGO DALLAS SAN FRANCISCO THE MACMILLAN CO. OF CANADA, LTD. TORONTO TRIGONOMETRY FOR THE USE OF COLLEGES AND SCHOOLS BY THE LATE I. TODHUNTER, M.A., F.R.S. HONORARY FELLOW OF ST. JOHN'S COLLEGE, CAMBRIDGE REVISED BY J. G. LEATHEM, M.A., D.Sc. FELLOW AND LECTURER OF ST. JOHN'S COLLEGE, CAMBRIDGE MACMILLAN AND CO., LIMITED ST. MARTIN'S STREET, LONDON 1914 SEL QA535 1914α COPYRIGHT. First Revised Edition 1901. GLASGOW: PRINTED AT THE UNIVERSITY PRESS BY ROBERT MACLEHOSE AND CO. LTD. PREFACE. THE present work is constructed on the same plan as my treatise on Plane Trigonometry, to which it is intended as a sequel; it contains all the propositions usually included under the head of Spherical Trigonometry, together with a large collection of examples for exercise. In the course of the work reference is made to preceding writers from whom assistance has been obtained; besides these writers I have consulted the treatises on Trigonometry by Lardner, Lefebure de Fourcy, and Snowball, and the Treatise on Geometry published in the Library of Useful Knowledge. The examples have been chiefly selected from the University and College Examination Papers. In the account of Napier's Rules of Circular Parts an explanation has been given of a method of proof devised by Napier, which seems to have been overlooked by most modern writers on the subject. I have had the advantage of access to an unprinted Memoir on this point by the late R. L. Ellis, of Trinity College; Mr. Ellis had in fact rediscovered for himself Napier's own method. For the use of this Memoir and for some valuable references on the subject I am indebted to the Dean of Ely. |