tan−1(13)\tan ^{-1}\left(\frac{1}{3}\right)tan−1(31)
tan−1(14)\tan ^{-1}\left(\frac{1}{4}\right)tan−1(41)
tan−1(35)\tan ^{-1}\left(\frac{3}{5}\right)tan−1(53)
tan−1(45)\tan ^{-1}\left(\frac{4}{5}\right)tan−1(54)