The probability of choosing randomly a number c from the set $\{1,2,3,..........9\}$ such that the quadratic equation $x^2+4x+c=0$ has real roots is:

Q. If $p$ and $q$ are chosen randomly from the set $\{1,2,3,4,5,6,7,8,9,10\}$, with replacement, determine the probability that the roots of the equation $x^2+px+q=0$ are real

Q. Determine the set of values of $k$ for which the given quadratic equation has real roots:
$x^2-kx+9=0$

Q. The set of values of k for which the given quadratic equation has real roots
$2x^2+kx+2=0$ is k $\le$ 9

Q.

If $\alpha ,\beta$ are the roots of the equation $3x^2+5x+4=0$, then the quadratic equation whose roots are ${\alpha }^2,{\beta }^2$

Q.

If the equation px² – 6x – 2 = 0 has real roots then, ________