What's \\(\mathbb{R} \times \mathbb{R}\\)? This is also known as \\(\mathbb{R} ^ 2\\).

It's the set of all pairs of real numbers.

It's the _Cartesian plane_, the set of all (x,y) pairs, for real x and y.

It's the set of all pairs of real numbers.

It's the _Cartesian plane_, the set of all (x,y) pairs, for real x and y.