
Geometry Geometry Math Forum 
 LinkBack  Thread Tools  Display Modes 
June 7th, 2018, 09:21 PM  #1 
Newbie Joined: Jun 2018 From: Mexico Posts: 1 Thanks: 0  intersecting circle formula proof(help)
Hi guys, can someone please tell me how to solve this question (Ayres, calculus, 5ed, question 24, chapter 4) let L1 and L2 be two intersecting circles determined by the equations X^2+Y^2+A1X+B1Y+C1=0 and X^2+Y^2+A2X+B2Y+C2=0 for any number k different that 1,show that X^2+Y^2+A1X+B1Y+C1+k(X^2+Y^2+A2X+B2Y+C2 )=0 is the equation of a circle through the intersection points L1 and L2 Last edited by skipjack; June 8th, 2018 at 11:55 PM. 
June 8th, 2018, 04:30 AM  #2 
Global Moderator Joined: Dec 2006 Posts: 19,042 Thanks: 1618 
Do you see why the points L1 and L2 have coordinates that satisfy the given equation?

June 8th, 2018, 04:37 PM  #3 
Global Moderator Joined: May 2007 Posts: 6,523 Thanks: 587 
Do you see that combining the expressions for the circles will end up as an expression for a different circle (if k is not 1)?


Tags 
circle, formula, intersecting, proofhelp 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
circle proof  markosheehan  Geometry  1  March 17th, 2017 01:03 PM 
New Formula of Circle?  azztereris  Geometry  5  November 20th, 2014 01:42 AM 
Circle Intersecting Axis  bilano99  Algebra  2  June 3rd, 2013 06:22 AM 
Prove the area formula of a circle?  wuzhe  Calculus  4  October 23rd, 2012 05:50 PM 
Circle Proof  Proclivitas  Algebra  4  March 20th, 2012 09:06 PM 