Etiology of "Quadratic" applied to Quad Formula

[Ringo847]

How did the quadratic equation and formula get its names? If "quad" means 4, how does this number apply to the equation? Was "Quad" once used to mean 2?

[MC Master of Ceremonies]

'Quad' as in 'square' as in squared, simlairly cubic equations start with and x cubed term.

[wolf_meister]

And if you want to see the quadratic formula or solve quadratics, here's a link:
http://www.1728.com/quadratc.htm

Here's a link for solving cubic equations
http://www.1728.com/cubic.htm

And relevant to the OP, a 4th power equation is called a "quartic" (since you were wondering when that '4' would enter the picture).

And yes there's a calculator for those too:
http://www.1728.com/quartic.htm

[Earl Snake-Hips Tucker]

As a side question, I'd also like to know the etymology of "etiology" as it relates to quadratic equations.:D