When two equations are perpendicular their slopes are 90° apart. In the equation y=5x-8 the slope is 5. The perpendicular slope is negative and the inverse of the given slope. So in this case the perpendicular line will have the slope = - 1/5
Discriminant = b^2 - 4ac, where a, b and c come from the form of the quadratic equation as ax^2 + bx + c
Discriminant = (4)^2 - 4(1)(5)
= 16 - 20
= -4
-4 < 0, therefor there are no roots
(If the discriminant = 0, then there is one root
If the discriminant > 0, there are two roots, and if it is a perfect square (eg. 4, 9, 16, etc.) then there are two rational roots
If the discriminant < 0, there are no roots)
