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Question
If x2 – 6x + 1 = 0, find the value of `x^2 + 1/x^2`.
Sum
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Solution
Given: x2 – 6x + 1 = 0
Step-wise calculation:
1. Divide the entire equation by (x) assuming (x ≠ 0):
`x - 6 + 1/x = 0`
2. Rewrite it as:
`x + 1/x = 6`
3. Square both sides:
`(x + 1/x)^2 = 6^2`
`x^2 + 2 + 1/x^2 = 36`
4. Subtract 2 from both sides:
`x^2 + 1/x^2 = 36 - 2`
`x^2 + 1/x^2 = 34`
Therefore, the value of `x^2 + 1/x^2` is 34.
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Chapter 3: Expansions - Exercise 3B [Page 72]
