1965 - James Gunn[?] and Bruce Peterson[?] use observations of the relatively low absorption of the blue component of the Lyman-alpha line[?] from 3C9[?] to strongly constrain the density and ionization state of the intergalactic medium
... non-zero. These solutions are also called the roots of the equation. The formula reads
<math>
x=\frac{-b \pm \sqrt {b^2-4ac}}{2a}
</math>
The term b2 ...