October 20th, 2011, 10:35 AM  #11  
Global Moderator Joined: Nov 2006 From: UTC 5 Posts: 16,046 Thanks: 938 Math Focus: Number theory, computational mathematics, combinatorics, FOM, symbolic logic, TCS, algorithms  Re: reverse n Quote:
 
October 20th, 2011, 10:40 AM  #12 
Newbie Joined: Oct 2011 Posts: 15 Thanks: 0  Re: reverse n
Is there a formula for reversing n?

October 20th, 2011, 01:07 PM  #13 
Math Team Joined: Apr 2010 Posts: 2,780 Thanks: 361  Re: reverse n
If you want a formula, a test for a palindrome is something like this: Let m+1 be the amount of digits of your number is the floorfunction returns the absolute value of x Evaluate If it is 0, the number is palindrome, else not. 
October 20th, 2011, 02:22 PM  #14  
Newbie Joined: Oct 2011 Posts: 15 Thanks: 0  Re: reverse n Quote:
 
October 20th, 2011, 02:42 PM  #15  
Math Team Joined: Apr 2010 Posts: 2,780 Thanks: 361  Re: reverse n Quote:
 
October 20th, 2011, 03:22 PM  #16  
Newbie Joined: Oct 2011 Posts: 15 Thanks: 0  Re: reverse n Quote:
 
October 20th, 2011, 05:08 PM  #17 
Global Moderator Joined: Nov 2006 From: UTC 5 Posts: 16,046 Thanks: 938 Math Focus: Number theory, computational mathematics, combinatorics, FOM, symbolic logic, TCS, algorithms  Re: reverse n
What, then, do you mean by "formula"? Not function, because I gave a function and it wasn't what you wanted. Not polynomial  there is no such polynomial.

October 20th, 2011, 05:22 PM  #18 
Newbie Joined: Oct 2011 Posts: 15 Thanks: 0  Re: reverse n
How would you calculate the reverse of n then?

October 21st, 2011, 01:10 AM  #19 
Senior Member Joined: May 2008 From: York, UK Posts: 1,300 Thanks: 0  Re: reverse n
To reverse a positive integer, you need to know what its base 10 representation is, and to do so you need to work out each digit of the integer in base 10. We can write down a formula for each digit: where is the coefficient of in the decimal expansion of There is always a largest nonzero which we will denote The reverse of is given by There is no 'neater' way of doing this.

October 21st, 2011, 05:59 AM  #20  
Newbie Joined: Oct 2011 Posts: 15 Thanks: 0  Re: reverse n Quote:
 

Tags 
reverse 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Reverse Quaternion Kinematics equations. BVP?  zuba  Applied Math  1  December 19th, 2012 02:58 AM 
reverse engineering a graph  ravynware  Algebra  0  April 15th, 2012 07:11 PM 
Reverse Modulo  swtrse  Number Theory  2  August 6th, 2009 04:53 AM 
Reverse solve f(x)?  NumberA  Algebra  5  April 19th, 2009 11:03 AM 
Reverse calculation  Clox  Algebra  2  January 23rd, 2008 12:24 AM 