Question

the value of k so that
${x}^{2} + 5kx + 16 = 0$
has no real root

Answer 1

Discriminant=0

${ {b}^{2} - 4ac} = 0 \\ \\ {25 {k}^{2} - 64} = 0 \\ \\ 25 {k}^{2} = 64 \\ \\ 5k = 8 \\ \\ k = \frac{8}{5}$