Exploring the Consequences of c^a=d^a & c^b=d^b in a Domain

  • Thread starter Metric_Space
  • Start date
  • Tags
    Domain
In summary, using Bezout's theorem, we can show that if c^a=d^a and c^b=d^b for integers a and b where gcd(a,b)=1, then it follows that c=d. This theorem is useful in abstract algebra and number theory.
  • #1
Metric_Space
98
0

Homework Statement



Let c and d be two non-zero elements of a domain D. If a and b are integers s.t gcd(a,b)=1, a>0, b > 0.

If we know c^a=d^a and c^b=d^b,

does it follow that c=d?

Homework Equations





The Attempt at a Solution



I'm thinking divinding the two might be pointless ..but subtracting might be a good idea.
c^a-c^b=d^a-d^b.

Somehow have to use the fact that we are working in a domain? The hint is to consider the Quot(D) and work in it.
 
Physics news on Phys.org
  • #2
actually...maybe I'm wrong, now I'm thinking to consider

(c^a)/(d^a)=(c^b)/(d^b) (given since non-zero) ...

I'm thinking if one messes around with this ...I'll get the answer. Does this seem on the right track?
 
  • #3
I'm getting then

(c^a)*(d^b)-(c^b)*(d^a)=0

I sbustituted in c^b=d^b to get

(c^a)*(d^b)-(d^b)*(d^a)=0

but that gets me back to where I started...
 
  • #4
Hi Metric Space! :smile:

Do you know Bezout's theorem? The one that says that if gcd(a,b)=1, then there exist integers k and l such that ka+lb=1.

I suggest you use this.
 
  • #5
interesting...I'll give it a shot -- I know the result but not the name...until now
 
  • #6
Well, actually, Bezout's theorem says that for each a and b, there exists k and l such that

[tex]ka+lb=gcd(a,b)[/tex]

I just applied it here with gcd(a,b)=1.

It's one of the more important theorems in abstract algebra and number theory. It's very useful!
 
  • #7
care to give another hint? I plugged that into one of my equations and just got a big mess
 
  • #8
Complete this:

[tex]c=c^{ak+lb}=...[/tex]
 
  • #9
ah...very useful hint

I solved for a before a in ak+lb=1...and that's what made a mess ...this hint 'solved' it - thanks!
 

1. What is the meaning of c^a=d^a and c^b=d^b in a domain?

C^a=d^a and c^b=d^b are mathematical expressions that represent equal values in a given domain. The symbol "^" is the exponent notation, where the value on the left is raised to the power of the value on the right.

2. What is the significance of exploring the consequences of c^a=d^a and c^b=d^b in a domain?

Exploring the consequences of c^a=d^a and c^b=d^b in a domain can help us understand the relationships between different variables and how they affect each other. It also allows us to make predictions and draw conclusions about the behavior of these variables.

3. Can you provide an example of c^a=d^a and c^b=d^b in a real-world scenario?

One example could be the relationship between the distance and time traveled by a moving object. If c represents the distance and d represents the time, then c^2=d^2 would mean that the square of the distance is equal to the square of the time. This could be applicable in a scenario where a car travels at a constant speed.

4. How does changing the values of a and b affect the consequences of c^a=d^a and c^b=d^b in a domain?

Changing the values of a and b can lead to different consequences in terms of the relationships between c and d. For example, if a is a larger value than b, c^a=d^a would result in a larger value for c compared to d, while c^b=d^b would result in a smaller value for c compared to d.

5. In what areas of science can exploring the consequences of c^a=d^a and c^b=d^b in a domain be useful?

Exploring the consequences of c^a=d^a and c^b=d^b in a domain can be useful in various fields of science including physics, chemistry, biology, and economics. It can help in understanding and predicting the behavior of variables in different systems and can also aid in making informed decisions in these fields.

Similar threads

  • Calculus and Beyond Homework Help
Replies
2
Views
386
  • Precalculus Mathematics Homework Help
Replies
6
Views
761
  • Calculus and Beyond Homework Help
Replies
3
Views
521
  • Calculus and Beyond Homework Help
Replies
22
Views
2K
  • Calculus and Beyond Homework Help
Replies
3
Views
798
  • Calculus and Beyond Homework Help
Replies
1
Views
866
  • Precalculus Mathematics Homework Help
Replies
5
Views
837
  • Calculus and Beyond Homework Help
Replies
1
Views
642
  • Math POTW for Secondary and High School Students
Replies
5
Views
967
  • Calculus and Beyond Homework Help
Replies
12
Views
2K
Back
Top