For a quadratic equation,if $\ldots \ldots \ldots \ldots,$ then both the roots are equal.

Find the nature of the roots of the following quadratic equation. If real roots exist,find them:
$2x^2 - 3x + 5 = 0$

If $64$ is the discriminant of $k x^{2}-4 x-4=0$,then the value of $k$ is ...........

Find the discriminant of the following quadratic equation: $5x^{2} + 2x - 1 = 0$.

State whether the following statements are true or false. Justify your answers.
$(i)$ Every quadratic equation has exactly one root.
$(ii)$ Every quadratic equation has at least one real root.

Find the roots of the following quadratic equation,if they exist,by the method of completing the square: $2x^{2} + x + 4 = 0$.