Osgood, William F. (William Fogg), 1864-1943, Graustein, William C. (William Caspar), 1888-1941, joint author · New York : The Macmillan Company · leaf 368
rried by (1). Solving equations (1) for x and y, and sub-stituting the values obtained, namely, x = -lx- I/, y = ^x + \y,in (2), we have, finally, (3) nx^^ + Q xy + 5 2/2 = 32 p\ This ellipse is as shown. One axis,OLy lies along the line x-\-y — 0.By adding equations (1), we have x-^y^-2x-{-2y, and… … 350 ANALYTIC GEOMETRY Consequently, a rotation of the (x, 2/)-plane about 0 through- 45°: (4) X, = V2 Vi V2 brings OL to lie along the positive axis of x. And a rotationof the (xy 2/)-plane about 0 through -|- 45°: (5) x, = x y V2 - ) , x -\-y V2 does the same for OL. The next step is to find the…
