InterviewSolution
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InterviewSolution
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If x2 + \(\frac{1}{x^2}\) = 23 find x + \(\frac{1}{x}\). |
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Answer» We have (a + b)2 = a2 + 2ab + b2 So (x + \(\frac{1}{x}\))2 = x2 + 2 x (x) x \(\frac{1}{x}\) + \(\frac{1}{x^2}\) = x2 + 2 + \(\frac{1}{x^2}\) = x2 + \(\frac{1}{x^2}\) + 2 = 23 + 2 ∵ x2 + \(\frac{1}{x^2}\) = 23 (x + \(\frac{1}{x}\))2 = 25 (x + \(\frac{1}{x}\))2 = 52 x + \(\frac{1}{x}\) = 5 |
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