Question

x^2 – rx + 1 = 0 has real roots and distinct root, then r does not lie between
(A) 1 and 2 (B) – 1 and 1 (C) – 2 and 2 (D) – 1 and 2

Answer 1

if the quadratic equation ax^2+bx+ c = 0 has two distinct real roots then the discriminant is positive. so b^2 - 4ac > 0
(-r)^2 -4 >0
r^2 > 4
r > 2 or r < -2

Answer 2

so c) then r does not lie between 2 and -2 ,