A general geometry and calculus : including book I. of the general geometry, treating of loci in a plane; and an elementary course in the differential and integral calculus (1881)
Olney, Edward, 1827-1887 · New York : Sheldon and Co. · leaf 50
he origin. If a be -f, the line makes an acute angle with the axisof abscissas, [i. e., it incHnes to the right, as thelines in Fig, 22), the tangent of an acute anglebeing 4-- If « be —, the angle is obtuse, [i. e.,the Hne inclines to the left, as in Fig. 23), since thetangent of an obtuse angle… … angle which the Hne makes with the axis ofordinates, since, in Fig. 21, the angle AHG = NHY =90° — NGX In this form, - isa
Geometry, Analytic · Calculus
Internet Archive · Boston College Libraries · Public Domain Mark 1.0. Free to use for anything.
