How to use Embedded MATLAB Function to calculate the maximum of a single-variable function

Good afternoon.

I'd like to know how to use Embedded MATLAB Function to calculate the maximum of a single-variable function, that is, if the function is y=f(x), I want to calculate [xmax, ymax]. I have made a m-file and it works when I run it from MATLAB, but when I type all the code in the Embedded MATLAB Function block, it doesn't work.

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function [Cpopt,TSRopt]=optimo(beta)

Cp=@(lambda) -0.5176*(116*(1/(lambda+0.08*beta)-0.035/(beta^3+1))-0.4*beta-5)*exp(-21*(1/(lambda+0.08*beta)-0.035/(beta^3+1)))-0.0068*lambda;

TSRopt=fminbnd(Cp,0,14);

Cpopt=0.5176*(116*(1/(TSRopt+0.08*beta)-0.035/(beta^3+1))-0.4*beta-5)*exp(-21*(1/(TSRopt+0.08*beta)-0.035/(beta^3+1)))+0.0068*TSRopt;

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This code should calculate the maximum of Cp=Cp(lambda), [lambda_opt, Cp_opt]. It seems that this block doesn't recognize "fminbnd" or the structure "function=@(variable).....".

NOTE: To calculate the maximum of Cp using "fminbnd" I have to calculate the minimum of -Cp.

Regards!