If √(x) - 1over√(x) = √(14) , then the value of √(x²+1overx²) is (correct to one decimal place):

If √(x) - 1over√(x) = √(14) , then the value of…

If $\sqrt{x}$ - $1\over\sqrt{x}$ = $\sqrt{14}$ , then the value of $\sqrt{x^2+{1\over{x^2}}}$ is (correct to one decimal place):

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Correct answer: A

Explanation

The correct answer is option 1 i.e. 15.9.

√x - 1/√x = √14

⇒ x + 1/x = (√14)² + 2 = 16

⇒ x² + 1/x² = (16)² - 2 = 254

⇒ √(x² + 1/x²) = √254 ≈ 15.9