If $\sqrt{x}-\frac{1}{\sqrt{x}}=\sqrt{7}

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Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If $\sqrt{x}-\frac{1}{\sqrt{x}}=\sqrt{7}$, then the value of $x^2+\frac{1}{x^2}$ is:

Options:

Correct Answer:

Explanation:

If $K-\frac{1}{K}=n$

then, $K^2+\frac{1}{K^2}$ = n² + 2

If $\sqrt{x}-\frac{1}{\sqrt{x}}=\sqrt{7}$,

then the value of $x^2+\frac{1}{x^2}$

= $x^2+\frac{1}{x^2}$ = $\sqrt{(\sqrt{7})^2 + 2}$ = 3