Roots can occur in a parabola in 3 different ways as shown in the diagram below: In diagram A, we can see that this parabola has 2 roots, diagram B has 1 root and diagram C has no roots.

Having lowered the bar for the sense in which we hope to solve a system of linear equations, one might wonder whether this quantum algorithm 3 offers a real advantage over classical computing at all.

The book showed how to solve polynomial equations, and algebraic methods of writing an expression in a simpler form, a tactic known as reduction. It also covered key concepts such as moving a ...