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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
Solution
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`
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