# Math Help - Rewriting a formula with beta and gammaln

1. ## Rewriting a formula with beta and gammaln

Hi there,

In the attached file, I've included a formula with beta and gammaln which has been rewritten for easier implementation in Excel. I get most of the rewriting, however I don't understand how multiplying A1, A2 and A4 yields the second part of the formula (the part after the + sign). Could anyone please help me with this? Any help would be much appreciated!

2. sry, I don't do word
I haven't paid for it, so I can't even open this up

3. Hi,

I've added the formulas as a JPG file. Are you able to open this?

4. without writing out your equations
I would venture to say that you need to

1 rewrite the B(a,b) as ${\Gamma(a)\Gamma(b)\over \Gamma(a+b)}$
and use

2 $\Gamma(a+1)=a\Gamma(a)$ which is just integration by parts