# Tag Info

Questions on polar coordinates, a coordinate system where points are represented by their distance from the origin ($r$) and the angle the line joining the point and the origin makes with the positive horizontal axis ($\theta$).
It is determined by the following diffeomorphism $$\boldsymbol\varphi \begin{bmatrix}\rho\\\phi \end{bmatrix} = \begin{bmatrix}\rho\cos\phi \\ \rho\sin\phi \end{bmatrix}: [0,\infty[ \times ]-\pi,\pi[ \to \mathbb{R}^2 \setminus \{\begin{bmatrix} 0\\0\end{bmatrix}\}$$ $0$ is called the pole of the polar coordinates.