Is this Infinite Product True or Not?

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In summary, The conversation is discussing the infinite product form for sine, which is given by f(x)=sin(x)=x(x-pi)(x-2pi)(x-3pi)(x-4pi)... However, it is pointed out that this series does not converge, as the absolute value of the terms keeps growing without bound. The correct infinite product form for sine is given by \sin(x)=x\prod_{n=1}^{\infty}\left(1-\frac{x^2}{(\pi n)^2} \right).
  • #1
Werg22
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Is this true?

f(x)=sin(x)=x(x-2pi)(x-4pi)(x-6pi)...

edit:

f(x)=sin(x)=x(x-pi)(x-2pi)(x-3pi)(x-4pi)...
 
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  • #2
It doesn't seem right to me, try x = 2pi.
 
  • #3
Sorry I did a mistake. I meant sin(x).
 
  • #4
Try x = pi.
 
  • #5
I'm affraid I do not see what you mean... the serie is infinite...
 
  • #6
No, your infintite product does not even converge.

Infinite product form for sine:

[tex]\sin(x)=x\prod_{n=1}^{\infty}\left(1-\frac{x^2}{(\pi n)^2} \right)[/tex]
 
Last edited:
  • #7
Werg22 said:
I'm affraid I do not see what you mean... the serie is infinite...
I was trying to point out that sin(pi) = 0 but your serie would never go to 0.
 
  • #8
Sorry what I really meant is f(x)=sin(x)=x(x-pi)(x-2pi)(x-3pi)(x-4pi)...

Really sorry.
 
  • #9
Werg22 said:
Sorry what I really meant is f(x)=sin(x)=x(x-pi)(x-2pi)(x-3pi)(x-4pi)...

Really sorry.

Still doesn't converge, the absolute value of the terms is growing without bound.
 

1. Is the concept of infinite product true or just a mathematical abstraction?

The concept of infinite product is both true and a mathematical abstraction. In mathematics, an infinite product represents the result of multiplying an infinite number of factors together. However, in reality, it is impossible to have an actual infinite number of factors. Therefore, the concept of infinite product is often used as a tool for mathematical analysis and is not always applicable to real-world scenarios.

2. Can an infinite product ever equal a finite number?

Yes, an infinite product can sometimes equal a finite number. This can only occur if the infinite product converges to a limit. In other words, if the value of the product approaches a finite number as the number of factors increases without bound, then it can be considered equal to that finite number.

3. Is an infinite product always divergent?

No, an infinite product is not always divergent. The convergence or divergence of an infinite product depends on the value of its individual factors. If the factors decrease in value at a fast enough rate, the product may converge to a finite number. However, if the factors increase in value or do not decrease fast enough, the product will diverge.

4. Can an infinite product have a negative value?

Yes, an infinite product can have a negative value. This can occur if the factors alternate between positive and negative values, resulting in the overall product being negative. However, if the factors are all positive or all negative, the product will also be positive.

5. How is the concept of infinite product used in real-world applications?

The concept of infinite product has several real-world applications, such as in finance and economics, where it is used to model compound interest or exponential growth. It is also used in physics and engineering to represent infinite series and to approximate functions. In computer science, infinite products are used in algorithms and data compression techniques.

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