Question

If - 1 by 2 is the root of the equation 2 x square + kx + 1 is equal to zero then find the value of k

Answer 1

$x = \frac{ - 1}{2} \: satisfies \: \: the \: \: equation \\ 2 \times {( \frac{ - 1}{2} )}^{2} + k \times \frac{ - 1}{2} + 1 = 0 \\ \frac{1}{2} - \frac{k}{2} + 1 = 0 \\ \frac{3}{2} - \frac{k}{2} = 0 \\ k = 3$