Q. The roots of $4x^{2} + 6px + 1 = 0$ are equal, then the value of $p$ is
A) 4/5
B) 1/3
C) $\pm 2/3$
D) 4/3
Explanation
(c)
Here, $b^{2} - 4ac = 0$
$\Rightarrow \ \ \ 36p^{2} - 4(4)(1) = 0$
$\Rightarrow \ \ 36p^{2} = 16$
$\Rightarrow \ \ p = \pm \frac{2}{3}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.