In Latvian mythology, Austras Koks ("tree of the east" or "tree of the dawn") was a tree that grew from the start of Saules' (the sun's) daily journey across the sky. It is usually considered an oak.
... to both sides, getting
<math>x^2+\frac{b}{a}x+\frac{b^2}{4a^2}=-\frac{c}{a}+\frac{b^2}{4a^2}.</math>
The left side is now a perfect square; it is the ...