Question

The equation 2x² + kx + 3 = 0 has two equal roots, then the value of k is:

Options

• `± sqrt6`

• ± 4

• `± 3sqrt2`

• `± 2sqrt6`

Answer 1

`± 2sqrt6`

Explanation:

Here a = 2, b = k, c = 3

Since the equation has two equal roots

∴ b² – 4AC = 0

⇒ (k)² – 4 × 2 × 3 = 0

⇒ k² = 24

⇒ k = `± sqrt24`

∴ k = `± sqrt(4 xx 6) = ± 2sqrt6`