wu :: forums
« wu :: forums - ABCD is a cyclic quadrilateral »

Welcome, Guest. Please Login or Register.
Nov 25th, 2024, 6:39am

RIDDLES SITE WRITE MATH! Home Home Help Help Search Search Members Members Login Login Register Register
   wu :: forums
   riddles
   medium
(Moderators: SMQ, Icarus, ThudnBlunder, william wu, Eigenray, towr, Grimbal)
   ABCD is a cyclic quadrilateral
« Previous topic | Next topic »
Pages: 1  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print
   Author  Topic: ABCD is a cyclic quadrilateral  (Read 3179 times)
tony123
Junior Member
**





   


Posts: 61
ABCD is a cyclic quadrilateral  
« on: Nov 19th, 2007, 9:34am »
Quote Quote Modify Modify

ABCD is a cyclic quadrilateral,  with side
AD= d
where d is the diameter of the circle. AB= a
 
BC= a
and CD= b
If a, b and d are integers a =\= b
 
(a)prove that d cannot be a prime number
         .
 
(b)determine the minimum value of d.
 
 
« Last Edit: Nov 19th, 2007, 1:20pm by tony123 » IP Logged
pex
Uberpuzzler
*****





   


Gender: male
Posts: 880
Re: ABCD is a cyclic quadrilateral  
« Reply #1 on: Nov 19th, 2007, 9:37am »
Quote Quote Modify Modify

on Nov 19th, 2007, 9:34am, tony123 wrote:
ABCD is a cyclic quadrilateral,  with side
AD= d
where d is the diameter of the circle. AB= a
 
BC= a
and CD= b
If a, b and d are integers a ≠ b
 
(a)prove that d cannot be a prime number
    .
 
(b)determine the minimum value of d.
 
Online

Not again... what is ≠ ? And does the "Online" at the end come from wherever you copied it from?
IP Logged
towr
wu::riddles Moderator
Uberpuzzler
*****



Some people are average, some are just mean.

   


Gender: male
Posts: 13730
Re: ABCD is a cyclic quadrilateral  
« Reply #2 on: Nov 19th, 2007, 10:00am »
Quote Quote Modify Modify

≠ is
 
[edit]It seems to be problem ten of http://cemc.uwaterloo.ca/english/contests/past_contest/1999/euclid.pdf[/edit]
« Last Edit: Nov 19th, 2007, 10:02am by towr » IP Logged

Wikipedia, Google, Mathworld, Integer sequence DB
thinktank
Newbie
*





   


Posts: 10
Re: ABCD is a cyclic quadrilateral  
« Reply #3 on: Nov 20th, 2007, 7:48am »
Quote Quote Modify Modify

The least value of d I think is 9
 
The proof for d not being a prime is also not that difficult...use the equation d(d-b)=2a2
« Last Edit: Nov 20th, 2007, 7:55am by thinktank » IP Logged
pex
Uberpuzzler
*****





   


Gender: male
Posts: 880
Re: ABCD is a cyclic quadrilateral  
« Reply #4 on: Nov 20th, 2007, 8:26am »
Quote Quote Modify Modify

on Nov 20th, 2007, 7:48am, thinktank wrote:
The least value of d I think is 9
 
The proof for d not being a prime is also not that difficult...use the equation d(d-b)=2a2

Aha... but isn't 8*(8-7)=2*22?
IP Logged
Pages: 1  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print

« Previous topic | Next topic »

Powered by YaBB 1 Gold - SP 1.4!
Forum software copyright © 2000-2004 Yet another Bulletin Board