If 2a - \(\frac{2}{a}\) + 4 = 0
Find a3 - \(\frac{1}{a^3}\) + 14
Answer & explanation
Correct answer: option 2
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