Math 403: Homework 7

Book problems: 3.12, 3.14, 3.16.

P1. Let A=(1,1), B=(3,3), and C=(3,0). Use the projection formula from class to find the three feet of the triangle ABC (the feet of the altitudes).

P2. Let l₁ and l₂ be distinct parallel lines, and suppose that the point Y does not lie on either line. Let P₁ and P₂ be the projections of Y onto the two lines. Show that the points Y, P₁, and P₂ are collinear.

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