Question

Complete the following activity to determine the nature of the roots of the quadratic equation x² + 2x – 9 = 0 :

Solution :

Compare x² + 2x – 9 = 0 with ax² + bx + c = 0

a = 1, b = 2, c = `square`

∴ b² – 4ac = (2)² – 4 × `square` × `square`

Δ = 4 + `square` = 40

∴ b² – 4ac > 0

∴ The roots of the equation are real and unequal.

Answer 1

Compare x² + 2x – 9 = 0 with ax² + bx + c = 0

a = 1, b = 2, c = – 9

∴ b² – 4ac = (2)² – 4 × 1 × – 9

Δ = 4 + 36 = 40

∴ b² – 4ac > 0

∴ The roots of the equation are real and unequal.