solve for unknown in math equation

[sl2obel2ts]

Is there a vi/function that I can use to solve for an unknown in an equation? I am currently using labview 7 express. (haven't opened 8.5 yet)

for example, I have

c as constant or input

c = x^2 + xcos(x)

and it is difficult to solve for x. How can I find what x is given c?

Thanks in advance.

[altenbach]

One problem is that there will be either zero, one or two solutions. Which one do you want? What is the valid range for x? For c?

In any case, a quick newton-raphson should find the solution quickly. I just tried and it seems to work fine.

What is your LabVIEW version?

[sl2obel2ts]

cool thanks

I am using labview 7.0. I found the function. I am having trouble what to put as function. Can you help me out with that?

[altenbach]

Well, you could just use wikipedia and make your own. 😉

Here's a very primitive version, simply add checks for diverging cases and bad estimates, etc.. Seems to find it in 5-8 iterations. You could even add analytical derivatives.

Message Edited by altenbach on 06-11-2008 10:20 AM

[sl2obel2ts]

thank you

[Kameralina]

Altenbach,

I love the animated gif image, what a great idea!

[rattlesnake]

labview 7.0 is good for equations and solving this equation is not a big deal but  i would like to suggest you to visit some good online websites through which you will be able to give and solve best questions . so i am giving you one of the links just go through it .

math equation solver

Amit28it