Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If 2a - \(\frac{2}{a}\) + 4 = 0

Find a3 - \(\frac{1}{a^3}\) + 14

Options:

-14

0

-12

14

Correct Answer:

0

Explanation:

Given, 2a - \(\frac{2}{a}\) + 4 = 0

2 (a - \(\frac{1}{a}\)) = -4

a - \(\frac{1}{a}\) = -2

a3 - \(\frac{1}{a^3}\) = (-2)3 + 3 × - 2 = -14

So, a3 - \(\frac{1}{a^3}\) + 14 = -14 + 14 = 0

 

Note → a - \(\frac{1}{a}\) = L, then a3 - \(\frac{1}{a^3}\) = L3 + 3L