Osgood, William F. (William Fogg), 1864-1943, Graustein, William C. (William Caspar), 1888-1941, joint author · New York : The Macmillan Company · leaf 204
t unknown, be {xi, 2/1)- Theequation of this tangent is then, by (12), § 2, (2) x^x-\-2y,y = Z. There are two conditions on the point P^, to serve as a meansof determining the values of x^ and y^. In the first place, thetangent (2) at P^ must go through the point (— 1, 2); hence (3) -0^1 + 42/1 =… … Fig. 8 186 ANALYTIC GEOMETRY and substitute its value in (4), we obtain, on simplification, thefollowing equation for yi: (6) 32/i2-42/1 +1 = 0. The roots of this equation are 2/1 = 1 and i/j = i; the corre-sponding values of Xi are, from (5), 1 and — |. Hence {xi, 2/1)= (1, 1) and (iCi, 7/i) =…
