Definition:Polar Coordinates/Polar Axis
< Definition:Polar Coordinates(Redirected from Definition:Initial Line)
Jump to navigation
Jump to search
Definition
Let $O$ be the pole of the polar coordinate plane.
A ray is drawn from $O$, usually to the right, and referred to as the polar axis.
Also known as
Some sources refer to the polar axis as the initial line.
Some use the term initial vector.
Linguistic Note
The plural of axis is axes, which is pronounced ax-eez not ax-iz.
Compare basis.
Sources
- 1933: D.M.Y. Sommerville: Analytical Conics (3rd ed.) ... (previous) ... (next): Chapter $\text I$. Coordinates: $2$. Coordinates
- 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): initial line