The equation should be:
∠ G ( s ) = tan − 1 ( Im k G ( s ) Re k G ( s ) ) = tan − 1 ( k Im G ( s ) k Re G ( s ) ) = tan − 1 ( Im G ( s ) Re G ( s ) ) , {\displaystyle \angle G(s)=\operatorname {tan} ^{-1}\left({\frac {\operatorname {Im} kG(s)}{\operatorname {Re} kG(s)}}\right)=\operatorname {tan} ^{-1}\left({\frac {k\operatorname {Im} G(s)}{k\operatorname {Re} G(s)}}\right)=\operatorname {tan} ^{-1}\left({\frac {\operatorname {Im} G(s)}{\operatorname {Re} G(s)}}\right),}
Return to errata.
