If m is a real number and 2x^2 + mx + 18 has two distinct real roots, then what are the possible values of m? Express your answer in interval notation.
To have two real roots, the discriminant must be > 0
So
m^2 - 4(2)(18) > 0
m^2 > 144
This will be true when m = ( -inf - 12)U ( 12, inf)
