# solving equation written in the functions

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Vijay Shankar Dwivedi on 28 Oct 2020
Edited: Aman Vyas on 3 Nov 2020
I want to solve three equations with three unknowns.
Force_x(x,y,z) == 0, Force_y(x,y,z) == 0, Force_z(x,y,z) == 0
vpasolve is not working here because Force_x works only when x y z are numbers, while vpasolve is passing symbols.
Help me with any other method or any modification.
my code:
[XX, YY] = vpasolve([Force_x(x,y,z)==0, Force_y(x,y,z)==0, Force_z(x,y,z)==0], [x, y, z], [0, 0, 0]);
error: Invalid arguments specified in evaluating the interpolant.
this error is due to symbols passed by Force_x.
##### 2 CommentsShowHide 1 older comment
Vijay Shankar Dwivedi on 28 Oct 2020
Force_x(x,y,z) is a function defined in anothe file which involves x, y, z.

Aman Vyas on 3 Nov 2020
Edited: Aman Vyas on 3 Nov 2020
Hi,
You can try following code:
syms x y z Force_x Force_y Force_z
[X Y Z] = vpasolve([Force_x==0,Force_y==0,Force_z ==0],[x y z],[0 0 0])
This would start produce generic output as shown :
X =
Empty sym: 0-by-1
Y =
Empty sym: 0-by-1
Z =
Empty sym: 0-by-1
See this if it matches the requirement in output. Once you start calling function Force_x and other two then it should start outputting correct value.
Hope it helps !

R2019b

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