Question

For what value Of k the quadratic equation x square +kx +4=0

Answer 1

$here \: a = 1 \\ b = k \\ c = 4 \\ by \: using \: discriminant \: formula \\ d = b {}^{2} - 4ac \\ 0 = k{}^{2} - 4 \times 1 \times 4 \\ 0 = k {}^{2} - 16 \\ 16 = k {}^{2} \\ \sqrt{16} = k \\ + - 4 = k$