Question

minimum possible value of K for which the equation 2x^2+6x+K=0 has complex roots?

Answer 1

for having complex roots Discriminant of quadratic equation must be less than zero
then what is result?

Answer 2

its 9/2 (4.5)<0. Will the answer be 4?

Answer 3

\[2x^2+6x+K=0\]
has complex roots when
the discriminate is <0
\[\Delta=b^2-4ac\]\[=6^2-4\times1\times K\]

Answer 4

because in the quadratic formula we have to take the square root of the discriminant ,
\[x=\frac{-b\pm\sqrt\Delta}{2a}\]

Answer 5

Little correction for the above post...
Δ=b^2 - 4ac = (6)^2 - 4(2)(K) < 0
Now you need to solve this: (6)^2 - 4(2)(K) < 0