What do i do here Constructing an Altitude and Median of a Triangle

For problems 29 - 31 the graph of a quadratic function y=ax^2 + bx + c is shown. tell whether the discriminant of ax^2 + bx + c = 0 is positive, negative, or zero.

With both problems. a.s.a.p directions on photo ^

Can anyone explain to me how to do this? anything will .