x = -1.15:0.001:1.15;
y1 = 1/2*(x.^2.^(1/3)+(x.^4.^(1/3)-4*x.^2+4).^(1/2));
y2 = 1/2*(x.^2.^(1/3)-(x.^4.^(1/3)-4*x.^2+4).^(1/2));
figure(2)
hold on
plot(x,y1,'.');
plot(x,y2,'.r');