The roots of the quadratic equation px^{2}-qx+r=0 are real and equal if:(a) p2=4ar(b) q2=4pr(c) -q2=4pr(d) p2>4qr

Correct answer is (b) q^{2 }= 4pr

The roots of the quadratic equation px^{2}-qx+r=0 are real and equal if q^{2}=4pr.