Question Number 136028 by mathmax by abdo last updated on 18/Mar/21
$$\mathrm{let}\:\mathrm{f}\left(\mathrm{x}\right)=\mathrm{e}^{−\mathrm{x}} \mathrm{arctan}\left(\mathrm{x}−\frac{\mathrm{1}}{\mathrm{x}}\right) \\ $$$$\mathrm{calculate}\:\mathrm{f}^{\left(\mathrm{n}\right)} \left(\mathrm{1}\right) \\ $$