Note: Australia is generally considered to be a continental landmass, rather than an island. If however one does count Australia among the islands it, not Greenland, would be the largest in the world (unless one also considered Antarctica an island).
... quadratic formula expresses the explicit solution(s) x to the quadratic equation
<math>ax^2+bx+c=0</math>
in terms of the coefficients a, b and c, ...