Plane Trigonometry and Numerical Computation

EVER since the publication of our Elementary Mathematical Analysis (1917) we have been asked by numerous teachers to publish separately, as a textbook in plane trigonometry, the material on trigonometry and logarithms of the text mentioned.

The present textbook is the direct outcome of these requests. Of course, such separate publication of material taken out of the body of another book necessitated some changes and an introductory chapter. As a matter of fact, however, we have found it desirable to make a number of changes and additions not required by the necessities of separate publication. As a result fully half of the material has been entirely rewritten, with the purpose of bringing the text abreast of the most recent tendencies in the teaching of trigonometry.

There is an increasing demand for a brief text emphasizing the numerical aspect of trigonometry and giving only so much of the theory as is necessary for a thorough understanding of the numerical applications. The material has therefore been arranged in such a way that the first six chapters give the essentials of a course in numerical trigonometry and logarithmic computation. The remainder of the theory usually given in the longer courses is contained in the last two chapters.

More emphasis than hitherto has been placed on the use of tables. For this purpose a table of squares and square roots has been added. Recent experience has emphasized the applications of trigonometry in navigation. We have accordingly added some material in the text on navigation, have introduced

the haversine, and have added a four-place table of haversines for the benefit of those teachers who feel that the use of the haversine in the solution of triangles is desirable. This material can, however, be readily omitted by any teacher who prefers to do so.

J. W. Young,
F. M. Morgan.

Hanover N.H.,
August, 1919.

PLANE TRIGONOMETRY AND NUMERICAL COMPUTATION