The discriminant of the equation $3x^2 - 6x + 4 = 0$ is .............

Find the roots of the following quadratic equation by using the quadratic formula,if they exist: $9x^{2} - 5x + 3 = 0$.

Find the discriminant of the following quadratic equation and hence determine the nature of the roots of the equation: $\frac{1}{4} x^{2} - 2x + 1 = 0$.

Find the discriminant of the following quadratic equation and hence determine the nature of the roots of the equation: $3x^{2} - 18x + 27 = 0$.

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

Find the discriminant of the following quadratic equation: $3x^{2} - 12x + 16 = 0$.