Question

If one zero of the quadratic polynomial (k – 1)x² + kx + 1 is –4 then the value of k is ______.

Options

• `(-5)/4`

• `5/4`

• `(-4)/3`

• `4/3`

Answer 1

If one zero of the quadratic polynomial (k – 1)x² + kx + 1 is –4 then the value of k is `underlinebb(5/4)`.

Explanation:

x = –4 satisfies (k – 1)x² + kx + 1 = 0.

∴ 16(k – 1) – 4k + 1 = 0

⇒ 12k = 15

⇒ `k = 5/4`