The unit lower half-disk is the portion of the complex plane satisfying .
Lower Half-Disk
See also
Disk, Real Axis, Semicircle, Unit Disk, Lower Half-Plane, Upper Half-DiskExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Lower Half-Disk." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/LowerHalf-Disk.html