 My Math Forum Finding equation of a circle without knowing its radius

 Calculus Calculus Math Forum

 March 7th, 2010, 10:23 AM #1 Newbie   Joined: Mar 2010 Posts: 2 Thanks: 0 Finding equation of a circle without knowing its radius Find the equation of the circle centered at (3,0) that intersects the curve y=x^2 at exactly one point. March 7th, 2010, 11:52 AM #2 Global Moderator   Joined: Oct 2008 From: London, Ontario, Canada - The Forest City Posts: 7,948 Thanks: 1139 Math Focus: Elementary mathematics and beyond Re: Finding equation of a circle without knowing its radius (x - 3)^2 + y^2 = r^2 x^2 - 6x + 9 + y^2 = r^2 2x - 6 + 2yy' = 0 y' = (6 - 2x)/(2y) and, from the other equation, y' = 2x. 2x = (6 - 2x)/(2y) 2x = (6 - 2x)/(2x^2) [sub in x^2 for y.] 2x - 6 + 4x^3 = 0, x = 1 so r^2 = 5. Tags circle, equation, finding, knowing, radius Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Similar Threads Thread Thread Starter Forum Replies Last Post alexmulo Algebra 8 August 23rd, 2012 06:45 AM daigo Algebra 1 February 23rd, 2012 03:14 PM soulrain Algebra 7 January 5th, 2012 07:51 PM thyrgle Algebra 4 May 16th, 2010 04:10 PM jokerthief Algebra 3 November 4th, 2007 02:52 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top      