Question

what is the value of the discriminant x^2-9

Answer 1

b^2 = 0
-4ac = -4(1)(-9) = 36
b^2-4ac = 36
note
sqrt (36) is 6

Answer 2

Small correction Damon:

the formula is

(-b + sqrt(b^2 - 4ac)) / 2a
-

Ans : + sqrt(36) / 2
-

ie + 6/2 and -6/3

Ans : + 3 and -3

Easier way: Method II

X^2 -9 = 0

X^2 = 9

X = Sqrt(9)

X = 3 or -3

Done!