tan−1(e−x)\tan ^{-1}\left(e^{-x}\right)tan−1(e−x)
tan(e−x)\tan \left(e^{-x}\right)tan(e−x)
tan−1(ex)\tan ^{-1}\left(e^{x}\right)tan−1(ex)
tan(ex)\tan \left(e^{x}\right)tan(ex)