Question

$\frac{a^n+b^n}{a^{n-1}+b^{n-1}}$ is the HM between $a$ and $b$, if $n$ is

• A. 0
• B. $\frac{1}{2}$
• C. $-\frac{1}{2}$
• D. 1

Answer 1

The correct option is A 0

Given
$\frac{2ab}{a+b}=\frac{a^n+b^n}{a^{n-1}+b^{n-1}}$

$\Rightarrow \frac{2}{\frac{1}{a}+\frac{1}{b}}=\frac{a^0+b^0}{a^{0-1}+b^{0-1}}=\frac{a^n+b^n}{a^{n-1}+b^{n-1}}$

$\therefore n=0$
$\therefore$ Ans. is option A.