Conjecture: Integer Solutions for a^3b-1 and ab^3+1

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In summary, to find all pairs of (a,b) you can use a nested loop, with the outer loop iterating through all possible values of a and the inner loop iterating through all possible values of b. This is useful for identifying and listing all possible combinations of two elements, and can be applied to non-numerical elements as well. To handle duplicate pairs, a conditional statement or data structure such as a set can be used. To optimize the process, efficient data structures and algorithms such as a hash table or combination-generating function can be utilized.
  • #1
Albert1
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$a,b\in N$
$\dfrac {a^3b-1}{a+1},\,\, and \,\, \,\,\dfrac {ab^3+1}{b-1}$ also $\in N$
find all pairs of $(a,b)$
 
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  • #2
Albert said:
$a,b\in N$
$\dfrac {a^3b-1}{a+1},\,\, and \,\, \,\,\dfrac {ab^3+1}{b-1}$ also $\in N$
find all pairs of $(a,b)$
hint:
$\because \dfrac{a^3b-1}{a+1}\in N,\,\,\therefore \,\,a+1\mid a^3b-1---(1)$

$\because\dfrac{ab^3+1}{b-1}\in N,\,\,\therefore \,\,b-1\mid ab^3+1---(2)$
 
  • #3
Albert said:
hint:
$\because \dfrac{a^3b-1}{a+1}\in N,\,\,\therefore \,\,a+1\mid a^3b-1---(1)$

$\because\dfrac{ab^3+1}{b-1}\in N,\,\,\therefore \,\,b-1\mid ab^3+1---(2)$
sol of others:
from (1):$a+1\mid a^3b-1- b(a+1)$
or :$a+1\mid ab(a^2-1)-(b+1)$
we get :$a+1\mid b+1-----(3)$
from (2):$b-1\mid ab^3+1- a(b-1)$
or :$b-1\mid ab(b^2-1)+(a+1)$
we get :$(b-1)\mid (a+1)\,\,\,from (3)\,\, \,\,this \,\,implies \,(b-1)\mid (b+1)-----(4)$
$b-1\mid b+1-(b-1)$
$b-1\mid 2---(5)$
$\therefore b=2,3---(6)$
put $(6) to (3)$
we have :$(a,b)=(2,2),(1,3),(3,3)$
 

FAQ: Conjecture: Integer Solutions for a^3b-1 and ab^3+1

How do you find all pairs of (a,b)?

To find all pairs of (a,b), you can use a nested loop. The outer loop will iterate through all possible values of a, and the inner loop will iterate through all possible values of b. This will generate all possible combinations of (a,b).

What is the purpose of finding all pairs of (a,b)?

The purpose of finding all pairs of (a,b) is to identify and list all possible combinations of two elements. This can be useful in various mathematical and scientific applications such as in probability, combinatorics, and data analysis.

How do you handle duplicate pairs when finding all pairs of (a,b)?

To handle duplicate pairs, you can use a conditional statement to check if the pair has already been added to the list. If not, then you can add the pair to the list of combinations. Additionally, you can use a data structure such as a set to store unique pairs and avoid duplicates.

Can you find all pairs of (a,b) for non-numerical elements?

Yes, you can find all pairs of (a,b) for non-numerical elements. The same principle of using a nested loop applies, but instead of iterating through numerical values, you would iterate through a list or array of non-numerical elements.

How do you optimize the process of finding all pairs of (a,b)?

To optimize the process of finding all pairs of (a,b), you can use efficient data structures and algorithms. For example, you could use a hash table to store and retrieve pairs in constant time, or you could use a combination-generating function to generate pairs on demand instead of storing them all in memory.

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