Proving the Validity of 5y^2 + 5y + 1 in Prime Numbers

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Homework Help Overview

The discussion revolves around the validity of the expression 5y^2 + 5y + 1 in relation to prime numbers, specifically questioning whether this expression yields prime numbers for all integer values of y greater than or equal to 1.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to prove the statement but expresses uncertainty about how to begin. Some participants question the completeness of the original statement, suggesting that the condition of primality may be missing. Others propose testing specific values of y to explore the expression's behavior.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the problem. Some guidance has been offered regarding testing values and considering divisibility, but no consensus has been reached on the validity of the expression.

Contextual Notes

Participants note potential missing information in the original statement and emphasize the importance of testing various values, including larger integers, to assess the expression's properties.

zoxee
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prove if the statement is true, else form it's negation and prove that is true:

## \forall y \in (x | x \in \mathbb Z , x \geq 1), 5y^2 + 5y + 1 ##

I think it's true, but I can't really even get started to prove it

I really suck at these and need help please, thank you!
 
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There is no statement that could be evaluated as true or false.
It is like "prove that this is true or false: 5".

I guess there is "is prime" missing. Did you test some numbers to check it? Don't just check small numbers, consider larger numbers as well.


Big hint:
There is no known useful formula to generate an arbitrary number of primes without excessive calculations.
 
Put this text into an *.vbs file and run it:

For y = 1 To 100
z = 5*y*y + 5*y + 1
if (z mod 11)=0 then MsgBox("f(" & y & ") is divisible by 11.")
if (z mod 19)=0 then MsgBox("f(" & y & ") is divisible by 19.")
Next
 
Where did "divisible by 5" and "divisible by 11" come from?
 

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