A TREATISE OF PLANE TRIGONOMETRY. TO WHICH IS PREFIXED A SUMMARY VIEW OF THE NATURE AND USE OF LOGARITHMS; BEING THE SECOND PART OF A COURSE OF MATHEMATICS, ADAPTED TO THE METHOD OF INSTRUCTION IN THE BY JEREMIAH DAY, D.D. LL.D. PRESIDENT OF YALE COLLEGE. Portland NEW HAVEN: PUBLISHED BY DURRIE AND PECK. NEW YORK-COLLINS, KEESE, and co. THE plan upon which this work was originally commenced, is continued in this second part of the course. As the single object is to provide for a class in college, such matter as is not embraced by this design is excluded. The mode of treating the subjects, for the reasons mentioned in the preface to Algebra, is, in a considerable degree, diffuse. It was thought better to err on this extreme, than on the other, especially in the early part of the course. The section on right angled triangles will probably be considered as needlessly minute. The solutions might, in all cases, be effected by the theorems which are given for oblique angled triangles. But the applications of rectangular trigonometry are so numerous, in navigation, surveying, astronomy, &c., that it was deemed important, to render familiar the various methods of stating the relations of the sides and angles; and especially to bring distinctly into view the principle on which most trigonometrical calculations are founded, the proportion between the parts of the given triangle, and a similar one formed from the sines, tangents, &c., in the tables. |