2013 RRB Allahabad

Question 78

If $$(a+ \frac{1}{a})^{2}=3$$ then the value of $$a^{3}+\frac{1}{a^{3}}$$ is

Solution

$$ a ^ {3} + b ^ {3} = (a+b) ( a^{2} + b^{2} - ab) $$

Substituting b = 1/a, we get the answer as 0

Share on Whatsapp Share on Whatsapp

Create a FREE account and get:

  • Download RRB Study Material PDF
  • 45+ RRB previous papers with solutions PDF
  • 300+ Online RRB Tests for Free

cracku

Boost your Prep!

Download App