Can anyone tell me what this symbol is?

[markraz]

Can anyone tell me what this symbol is? is this PI? 3.14?? thanks in advance

 

[Romsek]

It is a capital pi but it means that you take the product of the indexed terms.

For example $\displaystyle \prod \limits_{j=1}^n j= n!$

 

[ksdhart2]

The "capital pi" symbol is the multiplicative analogue of the sigma operator. That is to say:

$\displaystyle \sum\limits_{k = 1}^{n} k = 1 + 2 + 3 + \cdots + n = \frac{n(n+1)}{2}$

But:

$\displaystyle \prod \limits_{k=1}^{n} k = 1 \times 2 \times 3 \times \cdots \times n = n!$

 

[markraz]

The "capital pi" symbol is the multiplicative analogue of the sigma operator. That is to say:

$\displaystyle \sum\limits_{k = 1}^{n} k = 1 + 2 + 3 + \cdots + n = \frac{n(n+1)}{2}$

But:

$\displaystyle \prod \limits_{k=1}^{n} k = 1 \times 2 \times 3 \times \cdots \times n = n!$

thanks !!!

 

[pka]

Can anyone tell me what this symbol is? is this PI? 3.14?? thanks in advance

Using the classical Greek alphabet the capital $\displaystyle \Pi$ corresponds to the English P.
So it is natural to use it for Product. Thus $\displaystyle \prod\limits_{k = 1}^9 {{{(x + 1)}^k}}$ is the product of nine factors.
Just as $\displaystyle \Sigma$ corresponds to S, it is used to denote sums.