Deriviative or a product function

[ksnapp]

Hi

I need to take the partials of this function:

w = P(from i = 1 to n)(xi,g)

where that P is really a Pi symbol meaning that you take the products of the results of a function of xi and g. The i in xi is the indexing number. I need to get
dw/dx and dw/dg

I can't find anything anywhere on dealing with this kind of stuff.

 

[tkhunny]

It might be easier to try log(w).

 

[ksnapp]

really can you explain? that sounds helpful. thank you

 

[Deleted member 4993]

\(\displaystyle log(w) \ = \ \sum_{i=1}^{n}log(x_i,g)\)

 

[ksnapp]

If that works how i think it does, i get a sum of logs. thats great. but i don't know how to take a derivitive when there is a sum in the primal function.

 

[tkhunny]

\(\displaystyle \frac{w'}{w} = ??\)

Solve for w'.