Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If $\sqrt{x} -\frac{1}{\sqrt{x}}=\sqrt{3}$, then what is the value of $x^4 +\frac{1}{x^4}$?

Options:

531

7

623

527

Correct Answer:

527

Explanation:

If x - \(\frac{1}{x}\)  = n

then, $x^2 +\frac{1}{x^2}$ = n2 + 2

If $\sqrt{x} -\frac{1}{\sqrt{x}}=\sqrt{3}$

 x + \(\frac{1}{x}\) = (\(\sqrt {3}\))2 + 2 = 5

$x^2 +\frac{1}{x^2}$ = 52 - 2 = 23

$x^4 +\frac{1}{x^4}$ = 232 - 2 = 527