Question

How can you tell when a quadratic equation has one rational solution?​

Answer 1

b²-4ac=0

Explanation:

where

b²-4ac <0 it has no solution

b²-4ac >0 it has two solution

Answer 2

The discriminant equates to 0. (the expression underneath the square root sign will equal 0) This means that the curve will not cross the x-axis in two places.