function [ output ] = wielomianLagrangea( X , Y )
    %x[-2,-1,0,2]
    %y[0,1,1,2]
    %x^3/6 - x/6 + 1
    syms x;
    n = length(X);
    output = 0;
    for i = 1:n;
        y=1;
        for j = 1:n
                if j~=i
                    y = y * (x-X(j))/(X(i)+X(j));
                end
        end
        y = y * Y(i)
        output = output + y;
    end
    output = simplify(output);
    f = @(X)eval(output)
    z = x(1)-1:0.1:x(n)+1;
    plot(z,f(z),x,y,'v');

end