^rii-. Identifying this with yy = 2a(x + .r), y = —, x=+-Jl-Tm^. Eliminate/n. 1 10. Two tangents drawn to a parabola make complementary angleswith the axis of the parabola. Show that their chord of contactmust pass through the foot of the directrix. [The two tangents are represented bv y — mx + — ,… … Let the directiou-cosines of the parallel chords beI, m J and let (a, yS) be the middle point of amj one ofthem: its equation is whence x = a + lr, y = (i + mr.Combining these with y- = ^ax^ we have or mV + 2(^»i - 2al)r + ^^ - 4«a = 0,where r is now the distance from (a, /?) to Q or Q. Since (a,…
Geometry, Analytic
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