Question

How would you describe the roots of a quadratic equation?

Answer 1

Like:
\[\frac{ -3\pm \sqrt{17} }{ 4 }\]

Answer 2

Graphically, they (real zeroes) cross the x-axis. If the zeroes are complex, they do not touch the x-axis..
Numerically, the roots, x1 and x2, have the property that
f(x1)=0 and f(x2)=0, where f(x)=0 is the quadratic equation.