User:KhariDrake/sandbox

$$The Cartesian product $\mathbb{R} \times \mathbb{R} \times \mathbb{R}=\{(x, y, z) \mid x, y, z \in \mathbb{R}\}$ is the set of all ordered triples of real numbers and is denoted by $\mathbb{R}^{3}$. We have given a one-to-one correspondence between points $P$ in space and ordered triples $(a, b, c)$ in $\mathbb{R}^{3} .$ It is called a threedimensional rectangular coordinate system. Notice that, in terms of coordinates, the first octant can be described as the set of points whose coordinates are all positive.$$