function [y, err] = arctanseries(x,n)

if(x>=(-1))&(x<=1)
    power = [];
    nom = [];
    denom = [];
    neg = [];
    answer = [];
    
    % Vector neg, alternating values, 1 -1 1 -1 for arctanseries
    neg = ones(1,n);
    neg(2:2:end) = -1;
    
    % Vector power, starts at 1, increases by 2 for n-1 times
    power = 1:2:((2*n)-1);
    
    % Vector denom, denominator of the arctanseries. stats at 1
    denom = 1:2:((2*n)-1);
    
    % Vector nom, nominator equals x
    nom = (ones(1,n))*x;
    
    % solve arctan series 
    answer = nom .^ power;
    answer = answer .* neg;
    answer = sum(answer ./ denom);
    
    % ***Output***
    y = answer;
else
    err = error('Input Error: x must be between -1 and 1 inclusive')
end