Question

If the expansion of $6^{- 1/3}\left\lbrack 1 - \frac{x}{6} + \frac{2x^{2}}{6^{2}} - .... \right\rbrack$, the coefficient of y will be.

• A. $2 + \frac{3x^{2}}{4a^{2}} + ....$
• B. $1 + \frac{3x^{2}}{8a^{2}} + ....$
• C. $2 + \frac{x}{a} + \frac{3x^{2}}{4a^{2}} + ....$
• D. $2 - \frac{x}{a} + \frac{3x^{2}}{4a^{2}}$

Answer 1

Answer: (C)

$2 + \frac{x}{a} + \frac{3x^{2}}{4a^{2}} + ....$

Answer 2

2(5 – r) + (–1) r = 1 $\frac{256 - r}{2}$ 10 – 2r – r = 1 $\frac{r}{8}$

Thus coefficient of y is

$\because$.