Air Marshal is a three-star rank in the Royal Air Force. It is the second most senior rank active in the RAF today, after the inactivation of Marshal of the Royal Air Force[?] as a substantive rank in peacetime[?] during defence cuts of the 1990s.
... is equivalent to
<math>x^2+\frac{b}{a}x=-\frac{c}{a}.</math>
The equation is now in a form in which we can conveniently complete the square[?]. ...