Quadratic graph lines are U- or Ո-shaped, which is called a parabola. A linear graph can be drawn using only three points. A quadratic graph is a curve, so more points are plotted to support accuracy.

Plotting a graph takes time. Often mathematicians just want to know the key features. These are: shape, location and some key points (such as where the graph crosses the axes or turning points).

Various graph-based algorithms for semi-supervised learning have been proposed in the recent literature. They rely on the idea of building a graph whose nodes are data points (labeled and unlabeled) ...