x = 2
(2*x^2 - 3)^(1/3)/(0.2*x) % f(2)

%{
    But I want to evaluate my function at all the
    elements of the following vector A
%}
A = [1 -1 3]
(2*A.^2 - 3).^(1/3)./(0.2*A) % f(A)