Question

Determine the values of p for which the quadratic equaion $2x^2+px+8=0$ has real roots.

• A. $p\ge 8orp\le -8$
• B. $p\le -8$
• C. $p\ge \sqrt{3}$
• D. $p\ge -4$
• E. None of these

Answer 1

The correct option is A $p\ge 8orp\le -8$

For the roots to be real, The discriminant should be greater that or equal to zero.
For a quadratic equation, $a{x}^2+bx+c=0$
$D=b^2-4ac$
For the given quadratic eqn.
$D=p^2-4(2\times 8)\ge 0$
$p^2\ge 64$.