Question

If x = 3 is one of the roots of the quadratic equation x² – 2kx – 6 = 0, then the value of k is ______.

Options

• `-1/2`

• `1/2`

• 3

• 2

Answer 1

If x = 3 is one of the roots of the quadratic equation x² – 2kx – 6 = 0, then the value of k is `underlinebb(1/2)`.

Explanation:

Given that,

`\implies` x = 3 is root of the quadratic equation

x² – 2kx – 6 = 0

On putting x = 3 in the given equation,

`\implies` (3)² – 2(k)(3) – 6 = 0

`\implies` 9 – 6k – 6 = 0

`\implies` 6k = 3

`\implies` k = `3/6 = 1/2`