Determine if the following problem is symmetric and transitive

  • Thread starter Thread starter Meager
  • Start date Start date
  • Tags Tags
    Symmetric
Meager
Messages
2
Reaction score
0

Homework Statement



Suppose ~ is defined on the whole numbers by a~b iff ab2 is a perfect cube. Determine if ~ is
symmetric
transitive

Homework Equations


ab2 must ba2


The Attempt at a Solution



I tried using different numbers, but it isn't coming out as a perfect square.

For example, I said a=1
b=0........ Then this works.
Using other numbers it fails.

Should a=b?
 
Physics news on Phys.org
Welcome to PF!

Hi Meager! Welcome to PF! :smile:
Meager said:
Suppose ~ is defined on the whole numbers by a~b iff ab2 is a perfect cube. Determine if ~ is
symmetric
transitive

Hint: write a and b as a product of their prime factors. :wink:
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top