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If x2 + 1 = 2x , then the value of [ x2 + ( 1 / x2 ) ] is x2 - 3x + 1
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- 0
- 1
- 2
- –2
- 0
Correct Option: D
x2 + 1 = 2x (Given)
| ⇒ x + | = 2 ...(i) | |
| x |
| Expression = | x4 + | |||||
| x2 | ||||||
| x2 - 3x + 1 | ||||||
| = | ||||||
| x2 | ||||||
| x2 - 3x + 1 | ||||||
| Expression = | ||
| ( x2 + 1 - 3x ).x2 |
| Expression = | = | ||
| ( 2x - 3x ).x2 | -x3 |
| Expression = - |  |  | = - | | + | | ||||
| x3 | x3 | x3 |
| = - | | x3 + | | ||
| x3 |
| Expression = - |  | | x + | | 3 | - 3 | | x + | |  | |||
| x | x |
= – [23 – 3 × 2]
= – 2
