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If x^2 + 1/x^2 = 23, find the value of x + 1/x. - Mathematics

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Question

If `x^2 + 1/x^2 = 23`, find the value of `x + 1/x`.

Sum
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Solution

Given: `x^2 + 1/x^2 = 23`

Step-wise calculation:

1. Recall the identity:

`(x + 1/x)^2 = x^2 + 2 + 1/x^2`

2. Substitute the known value:

`(x + 1/x)^2 = 23 + 2`

`(x + 1/x)^2 = 25`

3. Take the square root:

`x + 1/x = ±5`

Thus, the value of `x + 1/x` is either 5 or –5.

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Chapter 3: Expansions - Exercise 3B [Page 72]

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Nootan Mathematics [English] Class 9 ICSE
Chapter 3 Expansions
Exercise 3B | Q 17. (i) | Page 72
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