Problem:
Find the first order expansion of the following function around 1:
$\tan ^{-1}\left(\frac{4 x}{5}\right)$
Answer:
$\frac{20 (x+4)}{281}-\tan ^{-1}\left(\frac{16}{5}\right)$
{'source': 'AMPS', 'file': 'amps/mathematica/calculus/series_expansion/46156.txt'}