How can I access openGL 4.1 on the Macbook Pro 15" Retina, Maverick OS, using xcode.

I'm a student that majors in computer science. I have been teaching my self openGL. I brought a book on opengl version 4. but i have no idea how to get access to openGL 4.0

I know this is the code to tell the machince that I want to use opengl version 4.1. but my mac has no idea about this syntax. My macbook pro can use version 4.1