? Undefined function or variable 'x'.

[tictaclp]

? Undefined function or variable 'x'.

function [ f, f1] = funyder( z )
%funcion y primera derivada del primer ejercicio
f=1-1/(1-x+2*z^2)
f1=(4*z-1)/(1-z+2*z^2)^2

this doesn't work .
Thanks

 

[MATLABdude]

function [ f, f1] = funyder( z )
%funcion y primera derivada del primer ejercicio
f=1-1/(1-x+2*z^2)
f1=(4*z-1)/(1-z+2*z^2)^2

this doesn't work .
Thanks

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