A treatise on special or elementary geometry (1877)
Olney, Edward, 1827-1887, Olney, Edward, 1827-1887. Elements of trigonometry, plane and spherical · New York : Sheldon · leaf 358
e-ment; cotangent means tangent of the complement; etc. The co-sine of 40° is the sine of 90° — 40°, or 50°; the cosine of 110° is thesine of 90° - 110°, or — 20°; the cotangent of 30° is the tangent of60° ; the cosecant of 200° is the secant of - 110°. 19. Construction of the Coniplefuentary… … to he reckoned around from right to left in this discussion. 1st. Let AP beany arc less than 90° ; then 90° — AP = aP is its complement. Now consideringa as the origin and P the termination ofthis complementary arc, Pd is its sine, atits tangent, Ot its secant, and ad its versed-sine. Hence, Pd^…
Geometry · Trigonometry
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
