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The roots of x^(2) - 2x-1= 0 are ""....

The roots of `x^(2) - 2x-1= 0` are `"_____"`.

A

`sqrt(2) + 1, sqrt(2) -1`

B

`1,sqrt(2)`

C

`1+sqrt(2), 1-sqrt(2)`

D

`2,1`

Text Solution

Verified by Experts

The correct Answer is:
C
Given `x^(2) - 2x-1 = 0`
`x = (2+-sqrt(4-4xx1xx(-1)))/(2xx1)`
`x = (2+-sqrt(8))/(2) = (2+-2sqrt(2))/(2) = 1+-sqrt(2)`
`x = 1+sqrt(2)` or `1 - sqrt(2)`.
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