+0  
 
0
34
2
avatar+311 

The maximum number of intersection points of 4 different circles is...

 Jan 17, 2019
 #1
avatar+16382 
+1

I believe it is 12 .   That is what I find.

 Jan 17, 2019
 #2
avatar+96201 
+1

Each pair of circles intersect twice

 

So.....we have a set of n circles and we want to choose any two of them  = C (n, 2)

 

And since each pair intersects twice, the number of intersection points = 2 C(n , 2)  =

 

2 n! / [ (n - 2)! * 2! ]   =  n! / ( n - 2)!  =   n ( n - 1)

 

So.....The max intersection points of n circles =  n(n - 1)

 

So.....  4(4 - 1)  =  4 (3)   =  12

 

Just as EP found !!!!

 

 

cool cool cool

 Jan 17, 2019
edited by CPhill  Jan 17, 2019

17 Online Users

avatar
avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.