Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If x2 - \(\sqrt[2]{10}\)x + 1 = 0, then find x - \(\frac{1}{x}\)

Options:

\(\sqrt {6}\) 

7

4

3\(\sqrt {6}\)

Correct Answer:

\(\sqrt {6}\) 

Explanation:

Formula → [If x + \(\frac{1}{x}\) = M, x - \(\frac{1}{x}\) = \(\sqrt {M^2 - 4}\)]

x2 - \(\sqrt[2]{10}\)x + 1 = 0

x2 + 1 = \(\sqrt[2]{10}\)x

x + \(\frac{1}{x}\) = \(\sqrt[2]{10}\)

x - \(\frac{1}{x}\) = \(\sqrt {(\sqrt[2]{10})^2 - 4}\)

x - \(\frac{1}{x}\) = \(\sqrt {6}\)