Find the discriminant. For no real roots, the discriminant must be negative. When you set the discriminant to be negative you then solve the inequality for k.
Find the discriminant. For no real roots, the discriminant must be negative. When you set the discriminant to be negative you then solve the inequality for k.
Oh looks like I didn't read it properly. Well assuming the variable is x then
x = (k^2 + 4)/k
in which case any non-zero value of k will allow x to be real. In the case of k = 0, x is undefined.