La maravillosa funci\'on y ecuaci\'on cuadr\'atica
  This article discusses some important applications of the quadratic function with the aim of highlighting the importance of cuadr\'aticas.- forms are also intended to show how a simple function covers virtually all areas of knowledge are presented. The interested reader can display more sites where this function is, perhaps growing populations or chaos, or perhaps in the fractal theory. 
Campo El\'ias Gonz\'alez Pineda
math.HO