Malcolm II of Scotland was king of Scotland from 1005 to 1034. He was the son of Kenneth III, first cousin of the previous king Kenneth II, and grandfather of his successor Duncan I. Malcolm united the Kingdom of Strathclyde and merged with the Kingdom of the Alba forming modern Scotland.
... 4ac is called the discriminant of the quadratic equation, because it discriminates between three qualitatively different cases:
If the discriminant is zero, then ...