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Home Limits, Analytic Geometry, and Approximations Parabolas Examples Example 2
 
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Example 2: Finding focus and directrix

Find the focus and directrix of the parabola

y = -¼x2

In Theorem 1, a = -½ and d = ¼a = -½. The focus is F(0, -½), and the directrix is y = ½.
Home Limits, Analytic Geometry, and Approximations Parabolas Examples Example 2

Last Update: 2006-11-15