Question 847229
a=3 b=-6 c = k

Find b^2 -4ac:

36 - 12k

This is our discriminant.  

Now when D > 0 we have two real solutions

36 -12k > 0

-12k > -36

k < 3


When D < 0 we have two complex solutions

36- 12k < 0

-12k < -36

k > 3

When D = 0 we have one real solution

36-12k= 0

36 = 12k

k = 3