What is the discriminant of f(x)= 10 minus 2x squared minus 6x

3x2 - 6x + p

the discriminant is
b2-4ac = 36-12p
To have a double root (2 equal roots)the
root is -b/2a and the discriminant is zero:
36-12p = 0
12p = 36
p = 3

3x2 -6x + 3
3(x2 - 2x) + 3
3(x2 - 2x + 1) + 3 - 3
3(x-1)2

a = 3, h = 1, k = 0