OF TRIGONOMETRY. WITH LOGARITHMIC AND OTHER TABLES. BY HENRY H. LUDLOW, First Lieutenant, Third Artillery, U. S. Army. WITH THE CO-OPERATION OF EDGAR W. BASS, Professor of Mathematics in the U. S. Military Academy. THIRD EDITION. NEW YORK: JOHN WILEY & SONS, 53 EAST TENTH ST. 1891. PREFACE. 1 IN preparing this text-book, Colonel EDGAR W. BASS, Professor of Mathematics in the U. S. Military Academy, West Point, N. Y., has been my collaborator, and the requirements of that Academy have almost entirely determined the extent and detail of treatment. The trigonometric functions are more completely explained than usual, each being illustrated and discussed separately. The usual chapter on the construction and use of trigonometric tables is omitted from the body of the work, and incorporated with the explanation of the tables. The spherical triangle proper is carefully distinguished from its corresponding trihedral angle at the centre of the sphere. Trigonometries by Chauvenet, Church, Olney, Newcomb, Wheeler, Todhunter, Beasley, and Hann have been freely consulted. The method in Newcomb's Trigonometry for deducing the developments of sine x and cosine x have been closely followed. Thanks are due to the instructors and students of mathematics in the U. S. Military Academy during the past three years, for many solutions and corrections. The demonstration of the 7th principle of right trihedrals, p. 130, is by Lieutenant E. D. Smith, 19th U. S. Infantry, to whom I am also indebted for valuable suggestions. NEW YORK CITY, April 15, 1890. HENRY H. LUDLOW. M306243 |