Multiple choice

Let $f(x)=\frac{x+x^{2}+...+x^{n}-n}{x-1},g(x)=(4^{n}+5^{n})^{1/n}$ and $\alpha $ and $\beta $ are the roots of equation $\lim_{x\rightarrow 1}f(x)=\lim_{n\rightarrow \infty }g(x)$, then the value of $\sum_{n=0}^{\infty }(\frac{1}{\alpha }+\frac{1}{\beta })^{n}$ is

  1. $\frac{5}{9}$
  2. $\frac{10}{3}$
  3. $\frac{10}{9}$
  4. $\frac{5}{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer