$\lim _{x \rightarrow 0} \frac{\left(1+\frac{x}{2}\right)^{5 / 7}-1}{x}=$
$\lim _{x \rightarrow 0} \frac{\left(1+\frac{x}{2}\right)^{5 / 7}-1}{x}=$
- $\frac{5}{7}$
- $\frac{10}{7}$
- $\frac{5}{14}$
- $\frac{5}{17}$
Solution
$\lim _{x \rightarrow 0} \frac{\left(1+\frac{x}{2}\right)^{5 / 7}-1}{x}$
Here, Limit is $\div$ form, so we can apply L-Hospital rule
$
\begin{aligned}
& =\lim _{x \rightarrow 0} \frac{\frac{5}{7}\left(1+\frac{x}{2}\right)^{-2 / 7} \cdot \frac{d}{d x}\left(\frac{x}{2}\right)-0}{1} \\
& =\lim _{x \rightarrow 0} \frac{5}{7}\left(1+\frac{x}{2}\right)^{-2 / 7} \cdot \frac{1}{2} \\
& =\frac{5}{7}(1+0)^{-2 / 7} \times \frac{1}{2}=\frac{5}{14}
\end{aligned}
$
Hence, option (3) is correct
Asked in: AP EAMCET 2020 (22 Sep Shift 2)
Practice more Limits questions on Aicharya