My Math Forum How to find the center?
 User Name Remember Me? Password

 Geometry Geometry Math Forum

 September 7th, 2015, 02:16 PM #1 Newbie   Joined: Mar 2015 From: Chicago Posts: 22 Thanks: 1 How to find the center? Find the center and radius of the circle with equation x2 + y2 − 8x + 18y + 16 = 0.
 September 7th, 2015, 02:23 PM #2 Senior Member   Joined: Jun 2015 From: England Posts: 829 Thanks: 244 So what is the equation of a circle with centre (X1, Y1) and radius R? You have to manipulate the given expression to arrive at that form. You can do this by completing the squares for (X, X1) and (Y,Y1) or by Multiplying out the equation for the above circle and equating coefficients.
September 7th, 2015, 09:40 PM   #3
Senior Member

Joined: Sep 2015
From: 4th Dimension

Posts: 146
Thanks: 13

Math Focus: Everything (a little bit)
Quote:
 Originally Posted by studiot So what is the equation of a circle with centre (X1, Y1) and radius R? You have to manipulate the given expression to arrive at that form. You can do this by completing the squares for (X, X1) and (Y,Y1) or by Multiplying out the equation for the above circle and equating coefficients.
Ya, either complete the squares or use general form of circle. The first one is preferred as it may tell you how general form works, later you can directly use general form.

 Tags center, find

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post fornuftit Algebra 2 May 23rd, 2012 10:23 PM 1101 Algebra 4 February 22nd, 2011 11:43 AM 1101 Algebra 0 June 10th, 2010 07:44 PM rowdy3 Calculus 2 May 5th, 2010 07:29 PM Igo Calculus 1 December 31st, 1969 04:00 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top