how to plot multiple 3d on one graph ?

I've try hold on but that isn't work. It turns out to be 2d plot

interval = [-5:0.1:5];

x = -5:0.1:5;
y = -5:0.1:5; 
[X,Y] = meshgrid(x,y);

z1 = acos((cos(interval)+cos((interval).')));
z2 = acos(-(cos(interval)+cos((interval).')));

figure(1);
plot3(X,Y,z2)
figure(2);
plot3(X,Y,z1)

Answer 1

[Ameer Hamza]

Following code works fine

interval = [-5:0.1:5];
x = -5:0.1:5;
y = -5:0.1:5; 
[X,Y] = meshgrid(x,y);
z1 = acos((cos(interval)+cos((interval).')));
z2 = acos(-(cos(interval)+cos((interval).')));

figure(1);
plot3(X,Y,z2)
hold on
plot3(X,Y,z1)

[Teerapong Poltue]

Oh, I got it thanks

[Ameer Hamza]

I am glad to be of help!

[Richard Summers]

Helped me too, nearly a year later...

Thanks muchly