# Thread: Help with a tricky implicit equation...

1. ## Help with a tricky implicit equation...

Hello,

I'm trying to solve this implicit equation for Ecarb:

(A*((D*ECARB)+(E*log((F+(G*ECARB))/H)))) = 1

I believe this is possible provided all other values are known.

Can anyone help with this?

Charles

2. ## Re: Help with a tricky implicit equation...

Are A,D, ... just constants?
Use:
log(a.b)=log(a)+log(b)
log(a/b)=log(a)-log(b)

I haven't checked if it's possible, try to do it with these rules, but maybe it's not possible.

EDIT:
Can you say more about A,D,...?

3. ## Re: Help with a tricky implicit equation...

Yes, A, D etc are all constants. Only ECARB is unknown. Thankyou

4. ## Re: Help with a tricky implicit equation...

The second term:
log((F+G.Ecarb)/H)=log(F+G.Ecarb)-log(H)
The problem is here:
log(F+G.Ecarb)
You can't split up Ecarb and the constants.

5. ## Re: Help with a tricky implicit equation...

Hi, thanks for the reply. That's what I noticed too. Apparently it's the Netwon-Raphson method to solve it.