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Question
If 3 is a root of the quadratic equation x2 – px + 3 = 0, then p is equal to ______.
Options
4
3
5
2
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Solution
If 3 is a root of the quadratic equation x2 – px + 3 = 0, then p is equal to 4.
Explanation:
x = 3 is a root of the equation
x2 – px + 3 = 0 ...(i)
Then x = 3 will satisfy equation (i)
∴ (3)2 – 3p + 3 = 0
9 – 3p + 3 = 0
3p = 12
`\implies` p = `12/3`
`\implies` p = 4
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