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Re: Perpendicular Lines
Posted:
Jan 2, 2013 10:00 PM



I would use the fact that with a circle, tangent lines are perpendicular to radii. Find lines tangent to a circle at suchandsuch a point on the circle in the plane... Guy Brandenburg, Washington, DC http://gfbrandenburg.wordpress.com/ http://home.earthlink.net/~gfbranden/GFB_Home_Page.html ============================
________________________________ From: Fred Siegeltuch <notesforfred@yahoo.com> To: "mathedcc@mathforum.org" <mathedcc@mathforum.org> Sent: Wednesday, January 2, 2013 5:47 PM Subject: Perpendicular Lines
Hi all,
I've seen tons of examples of math modeling where parallel lines arise and have a natural interpretation but I could use help in finding ones where the product of the slopes equals 1 is useful in modeling other than in doing bare geometry problems algebraically. I'd appreciate an example where this fact was used in such a way that covering this material didn't seem tangential (please forgive the pun) to a modeling perspective for algebra. I could try to embellish a problem that tries to find the tangent line to a circle or circular cylinder with a specific given radius but as of now I'm trying to do better. Ideally this should be no higher than the intermediate algebra level.
Thanks,
Fred Siegeltuch City Colleges of Chicago



