Take the 2-minute tour ×
Mathematica Stack Exchange is a question and answer site for users of Mathematica. It's 100% free, no registration required.

I tried to solve the following equation with Mathematica's solve:

Solve[K*(2*Tan[L/2*Sqrt[P/(EI)]]-L*Sqrt[P/(EI)])+4*P*Sqrt[P/(EI)] == 0, P]

It gave the following error:

Solve::nsmet: This system cannot be solved with the methods available to
Solve.

I do not see any strange functions being called here, and I am curious about what properties make this expression difficult for Mathematica.

share|improve this question
add comment

1 Answer

up vote 12 down vote accepted

This is in fact more of a math question than a Mathematica one.

Your equation is one of the many transcendental equations (as opposed to being an algebraic equation that can be solved with methods for solving polynomials) that one cannot solve with the usual ways taught in undergraduate algebra/precalculus courses. In particular, the difficulty in solving this transcendental equation is that your P is inside a square root, outside a square root, and inside a square root inside a tangent (and the tangent is what makes this equation transcendental).

Mathematica will also be hard-pressed to solve this symbolically, so don't hope for an explicit solution.

Thus, you might have to content yourself with using FindRoot[] for a numerical solution. You might wish to plot the left hand side of your equation with specific values of your other parameters to assist in searching for this equation's roots.

As an aside, K is a reserved System` symbol; consider using a different name for that parameter.

share|improve this answer
3  
Dear tumadre, welcome to Mathematica.SE! Please consider registering your account. That way, you will be able to do more on the site over time, as you accumulate reputation. Judging by these first two answers, I expect you will be accumulating more reputation before long. –  Verbeia Feb 11 '13 at 5:32
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.