Solving a formula in Matlab

Hello everyone,

In the following formula : X= 2y + 10 log(1+ E/S)

I want the user to input X, y, and S. Is there anyway i can get matlab to give me the value of E without having to rewrite the formula?

Thank you so much!

[Torsten]

Maybe by using MATLAB's "solve" ?

Best wishes

Torsten.

[Roger Stafford]

It seems a shame not to use such a simple inverse formula as:

   E = S*(exp((X-2*y)/10)-1);

assuming your log is the natural logarithm. Otherwise:

   E = S*(10^((X-2*y)/10)-1);

Answer 1

[Giorgos Papakonstantinou]

x = input('Enter the value of x: '); % request user input
y = input('Enter the value of y: ');
S = input('Enter the value of S: ');

f = @(E) 2.*y + 10*log(1+ E./S) - x; % create an anonymous function

[Eval, fval]= fsolve(f, 1); % solve your equation

or you can also:

syms E
f = 2.*y + 10*log(1+ E./S) == x;
solve(f, E)

If log refers to the base of 10 rewrite f by replacing log with log10.