A parabola, a triangle, and a circle

Let P be a parabola. Draw tangents to P at three different points. These three lines intersect to form a triangle. Theorem: The circumcircle of this triangle passes through the focus of P. [1] In the image above, the dashed lines are tangents and the black dot is the focus of the parabola. (See this […] The post A parabola, a triangle, and a circle first appeared on John D. Cook....

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