Question Number 48687 by gunawan last updated on 27/Nov/18
$${f}\left({x}\right)=\mathrm{sin}\:\left({x}\right) \\ $$$${f}\left({x}\right)+{f}'\left(\frac{\mathrm{1}}{{x}}\right)=\frac{\mathrm{1}}{\mathrm{2}}\sqrt{\mathrm{2}} \\ $$$$\mathrm{find}\:{x}? \\ $$