A polynomial of degree 4 can have up to 3 local maxima/minima.
Any 4 points in the Cartesian plane determine a unique equation that is of degree at most three (i.e., a "cubic" equation). It is, of course, possible that the 4 points actually lie on a degree two ("quadratic"), a degree one ("linear"), or a degree zero ("constant") equation. However, if the 4 points do not lie on a constant, linear, or quadratic curve, then they will like on a unique cubic curve. In general, N points will determine a unique curve of degree at most (N-1).
points : infinite lines : 4 vertices : 4
4 points
4 weight watchers points
4 points
4
A starfish has a total of five points
4 points.
4 points
4 points define a plane.
In cribbage, you can score 4 points for a run of 4 in your hand.
4 points