Re: rearrange tough equation

It might help to read this LaTeXed, is your equation $\displaystyle \displaystyle \begin{align*} A = 10^{K\,e^{c_1V} + e^{c_2V}} \end{align*}$?

Re: rearrange tough equation

hi, yes that is the correct equation. thanks for that.

Re: rearrange tough equation

I don't think it's possible to isolate V in this case. Can you tell us where this problem came from please?

Re: rearrange tough equation

Thanks for your reply. It is a fitted surface equation. Can the Lambert W function be used at all?

Re: rearrange tough equation

Hi, could someone provide some more guidance on this problem please? If it is impossible to rearrange, then what approach can I take to solve it? thanks again.

Re: rearrange tough equation

Quote:

Originally Posted by

**dave2014** Hi, could someone provide some more guidance on this problem please? If it is impossible to rearrange, then what approach can I take to solve it? thanks again.

Lambert isn't going to help here. I know of no way to solve for V. If you had some numbers for the other variables then you might be able to do it numerically.

-Dan

Re: rearrange tough equation

Please indicate as what have you done so far. I feel there is something missing in the question. I don't think we can isolate V in its present form.

Re: rearrange tough equation

Quote:

Originally Posted by

**topsquark** Lambert isn't going to help here. I know of no way to solve for V. If you had some numbers for the other variables then you might be able to do it numerically.

-Dan

Hi Dan, thanks for your reply. I have the values for c1 and c2 only, not K or V. Does that help at all?

Re: rearrange tough equation

People are saying this is impossible so maybe I'm missreading it but here's my attempt

$\displaystyle \displaystyle \begin{align*} A = 10^{K\,e^{c_1V} + e^{c_2V}} \end{align*}$

Let $\displaystyle b=Ke^{c_1}, a=e^{c_2}$

$\displaystyle A=10^{be^V+ae^V}$

$\displaystyle A=10^{(b+a)e^V}$

Let $\displaystyle F=10^{a+b}$

$\displaystyle A=F10^{e^V}$

$\displaystyle \frac{A}{F}=10^{e^V}$

$\displaystyle log_{10}\frac{A}{F}=e^V$

$\displaystyle log_e(log_{10}\frac{A}{F})=V$

Re: rearrange tough equation

After your substitution, you would have instead:

$\displaystyle A=10^{b^V+a^V}$

Re: rearrange tough equation

Quote:

Originally Posted by

**MarkFL** After your substitution, you would have instead:

$\displaystyle A=10^{b^V+a^V}$

Ah you're right. Thanks, I'm mixing up indices rules.

Re: rearrange tough equation

Quote:

Originally Posted by

**dave2014** Hi Dan, thanks for your reply. I have the values for c1 and c2 only, not K or V. Does that help at all?

Actually I also know values for K and A, it is just V I do not know. Thanks everyone for your efforts so far, does knowing K, A, c1, and c2 help at all? Thanks.