Alpin II of Dalriada, also known as Alpin mac Eochaid was the father of Kenneth I of Scotland who united the Kingdom of the Scots and the Picts. Alpin II reigned from about 839-841.
... impossible to divide by it.)
The symbol
<math>\pm \sqrt {b^2-4ac}</math>
in the formula should be understood as "either of those element(s) of the field ...