# got stuck in equation

Tim Roberts timr at probo.com
Tue Jan 1 22:09:01 CET 2013

```usamazohad at gmail.com wrote:
>
>i know very litle about programing. still learning from tutorials. u can call
>me a beginner.
>now i need to solve this equation so that i can put this in python but the
>formula of design is very complex
>
>Formula is :
>
>log(W18) = (Z)(S)+9.36log(SN+1) -2.0+(log(dpsi/(4.5-1.5))(/(.40+1094/(SN+1)^2.5)+2.32log(Mr-)-8.07
>
>every thing is constant except this SN. . i want to seperate SN like SN=
>rest of the stuff. how can i seprate it because manualy its impossible to
>take SN out.

Right.  Algebraically, it isn't practical to solve this for SN.  That
probably means you're going to need a iterative solution.  That is, you
start with a guess, see how far off you are, and refine the guess until you
narrow in on a solution.  That means you'll have to figure out whether
raising SN gets you closer or farther away from a solution.
--
Tim Roberts, timr at probo.com
Providenza & Boekelheide, Inc.

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