The quadratic formula for a quadratic equation in the form of \(ax^2 + bx + c = 0\) is \(x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\). The first solution is \(x = \frac ...

Following work of Heindl and of Powell and Sabin, each triangle of an arbitrary (regular) triangulation $\Delta$ of a polygonal region $\Omega$ in $\Bbb R^2$ is subdivided into twelve triangles, using ...