Question Number 125503 by mathmax by abdo last updated on 11/Dec/20
$$\mathrm{explicit}\:\:\mathrm{f}\left(\mathrm{x}\right)=\int_{\mathrm{0}} ^{\mathrm{2}\pi} \mathrm{ln}\left(\mathrm{x}^{\mathrm{2}} −\mathrm{2xcos}\theta\:+\mathrm{1}\right)\mathrm{d}\theta\:\:\:\left(\mathrm{xreal}\right) \\ $$