3x2 + 2x – 1 = 0

(ii) 3x² + 2x – 1 = 0

Sol. 3x² + 2x – 1 = 0

Comparing with ax² + bx + c = 0 we have a = 3, b = 2, c = – 1

∆  = b² – 4ac

= (2)² – 4 (3) (– 1)

= 4 + 12

= 16

∴ ∆  = 16