Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If $\frac{a}{b}+\frac{b}{a}=-1$ and a - b = 2, then the value of $a^3 - b^3$ is:

Options:

0

$\frac{1}{2}$

1

-1

Correct Answer:

0

Explanation:

 $\frac{a}{b}+\frac{b}{a}=-1$ 

\(\frac{a^2 + b^2}{ab}\) = -1

a2 + b2 = -ab

a - b = 2

a3 - b3 = ( a - b ) ( a2 + b2 + ab )

a3 - b3 = ( 2 ) ( -ab + ab )

a3 - b3 = 0