For which zzz is arg(z)=arg(zˉ)\text{arg}(z) = \text{arg}(\bar{z})arg(z)=arg(zˉ)?
zzz is any complex number
extIm(z)=0 ext{Im}(z) = 0extIm(z)=0
extRe(z)=0 ext{Re}(z) = 0extRe(z)=0
∣z∣=1|z| = 1∣z∣=1