Solving equation with one variable but it is present in the equation twice

Hello,

I can solve equation using pen and paper but I have set of data where i have to apply that equation but the probblem is that the unknow vairable in the equation is presnet twice and i dont know how to do it in matlab, here is the equation in picture,

Now Vout is known and it is the set of data which needs to be converted in to resistance, as you can see this is a wheatstone bridge equation. I would like to find x, i can do it manually on paper but don't know how to do it on matlab.

Thank you fo the help in advance

Answer 1

[Torsten]

syms x Vout
eqn = Vout == (0.5 - x/(x+1000))*3.3*128;
x = solve(eqn,x)

x = 

x = matlabFunction(x)

x = function_handle with value:
    @(Vout)-(Vout.*5.0e+3-1.056e+6)./(Vout.*5.0+1.056e+3)

x(100)

ans = 357.3265

Answer 2

[David Hill]

It is easy to just solve for x in your equation and have an equation in Vout.

f=@(Vout)(211200-1000*Vout)./(Vout+211.2);
f(100)

ans = 357.3265

[Hiril Patel]

sorry but i could not follow what you did here, can you elaborate.

For example if i take Vout = 0.000656 then using hand calculation I get x = 999.9948( i need high decimal value for precision reason)

[Hiril Patel]

Got the value that i needed, but still cannot understand how did you got this:

f=@(Vout)(211200-1000*Vout)./(Vout+211.2);

looking for information to understand

Thank you you solved my problem

[Torsten]

You wrote you could solve the equation for x using pencil and paper. Then do it - this is the result you will get:

x = (211200-1000*Vout)./(Vout+211.2)