Solved
There is no keyword named [_], Solving unknown variable
See snip below & attached. I'm trying to solve for z_pna, such that the sum of the tension forces equals the sum of the compression forces.
The variable you want to solve for needs to be part of the equation. That is not the case above. You should have z_pna be a parameter to both SigmaT and SigmaC. This in turn means that also Tsr and Csrw must be functions, with z_pna as a parameter.
Considering that all other items are numerically defined, there's no need to try to solve this symbolically (which you do when you use that arrow). Better try a numerical solver, such as the root() function.
And when you really do want to use the symbolic solver:
1. You need to use the 'solve' keyword.
2. You should consider that the symbolic processor does not know about units by default, and while there is a setting to let it take account of them, sometimes it simply doesn't work.
Success!
Luc
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