How to use fsolve

 After that I get my target equation  which has only 1 Unknown. So something like:

eqn=[x^2];
solution=fsolve(@(x) eqn, startx);

Unfortunatlly that does not work. Thank You very much!

[Stephen23]

The fsolve help states that the first input must be "specified as a function handle or function name", and all of the examples show fsolve being used with function handles. You should learn about function handles:

https://www.mathworks.com/help/matlab/function-handles.html

Also note that the square brackets are totally superfluous:

https://www.mathworks.com/matlabcentral/answers/35676-why-not-use-square-brackets

Answer 1

[Torsten]

eqn5 = @(x)x^2+1;
solution = fsolve(eqn5, startx);

Best wishes

Torsten.