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SSC CHSL 2023 PYQ — Question 61

SSC CHSL - 10 March 2023 - Shift 3 • Quantitative Aptitude • Q61

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If x2+1x2=38x^{2}+\frac{1}{x^{2}}=38, then what is the value of x−1xx-\frac{1}{x}?

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Correct answer: A

Explanation

The correct answer is option 1 i.e. 6.

(x - 1/x)2 = x2 - 2(x)(1/x) + (1/x)2

⇒ (x - 1/x)2 = (x2 + 1/x2) - 2 = 38 - 2 = 36

⇒ x - 1/x = √36 = 6

Therefore, the value of x - 1/x is 6.