Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If $x^2 +\frac{1}{x^2}= 38,$ then what is the value of $\begin{vmatrix}x-\frac{1}{x}\end{vmatrix}$ ?

Options:

5

9

6

4

Correct Answer:

6

Explanation:

If x2 + \(\frac{1}{x^2}\) = b

Then, x + \(\frac{1}{x}\) = \(\sqrt {b - 2}\)

If $x^2 +\frac{1}{x^2}= 38,$

Then, x - \(\frac{1}{x}\) =  \(\sqrt {38 - 2}\) = 6