JEE Advance - Mathematics (1994 - No. 22)
If p, q, r are + ve and are on A.P., the roots of quadratic equation $$p{x^2} + qx + r = 0$$ are all real for
$$\left| {{r \over p} - 7} \right| \ge 4\sqrt 3 $$
$$\left| {{p \over r} - 7} \right| \ge 4\sqrt 3 $$
all p and r
no p and r