y2 – 4y – 1 = 0


(i) y2 – 4y – 1 = 0

Sol. y2 – 4y – 1 = 0
Comparing with ay2 + by + c = 0 we have a = 1, b = – 4, c = – 1
 = b2 – 4ac
= (– 4)2 – 4 (1) (-1)
= 16 + 4
= 20
∴ ∆  > 0

Hence roots of the quadratic equation are real and unequal.