function [isPrime,divisor] = testPrime(n)
% This is a function that takes as input an integer n >= 2
% and determines whether n is prime. 
% returns the variables 'maybePrime' and 'divisor' as output
%
% A Matlab function, if it occupies its own file, 
% should have the same name as the M-file 
% (in this case, 'testPrime'). 
%
% We can then call this function from other programs, 
% or from the command line


    isPrime = true; % after the code runs, the function returns
                    % the current value of maybePrime
    divisor = NaN;  % If we find a divisor, return the smallest one. 

                                        
    for i = 2:sqrt(n)
        if mod(n,i) == 0
            isPrime = false; 
            divisor = i; 
            return % return instantly ends the routine and
                   % returns the value of maybePrime
        end
    end

end