PLANE AND SPHERICAL

TRIGONOMETRY

BY

G. A. WENTWORTH, A.M.

AUTHOR OF A SERIES OF TEXT-BOOKS IN MATHEMATICS

REVISED EDITION

BOSTON, U.S.A., AND LONDON

GINN & COMPANY, PUBLISHERS

1901

HARVARD COLLEGE LIBRARY

GIFT OF

MISS ELLEN L. WENTWORTH

MAY 8 1939

Entered, according to Act of Congress, in the year 1882, by
G. A. WENTWORTH

in the Office of the Librarian of Congress, at Washington.

Copyright, 1895, by G. A. WENTWORTH.

Lompas

PREFACE.

IN

N preparing this work the aim has been to furnish just so much
of Trigonometry as is actually taught in our best schools and
colleges. Consequently, all investigations that are important only
for the special student have been omitted, except the development of
functions in series. The principles have been unfolded with the
utmost brevity consistent with simplicity and clearness, and inter-
esting problems have been selected with a view to awaken a real
love for the study. Much time and labor have been spent in devising
the simplest proofs for the propositions, and in exhibiting the best
methods of arranging the logarithmic work.

The author is under particular obligation for assistance to G. A.
Hill, A.M., of Cambridge, Mass., to Prof. James L. Patterson, of
Schenectady, N.Y., to Dr. F. N. Cole, of Ann Arbor, Mich., and to
Prof. S. F. Norris, of Baltimore, Md.

EXETER, N.H., July, 1895.

G. A. WENTWORTH.

Note to second revised Edition

under abligation

The author is un

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