polar axis

American  

noun

Mathematics.

1. the fixed line, usually horizontal, from which the angle made by the radius vector is measured in a polar coordinate system.

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polar axis British  

noun

1. the fixed line in a system of polar coordinates from which the polar angle, θ, is measured anticlockwise

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Etymology

Origin of polar axis

First recorded in 1890–95

Example Sentences

The directrix will be parallel to the polar axis.

From Textbooks • Dec. 21, 2021

If the angle is positive, then measure the angle from the polar axis in a counterclockwise direction.

From Textbooks • Mar. 30, 2016

This graph has symmetry with respect to the polar axis, the origin, and the vertical line going through the pole.

From Textbooks • Mar. 30, 2016

Perhaps the graph does cross the polar axis, but not at the pole.

From Textbooks • Feb. 13, 2015

The polar axis of the Crossley reflector is a long, hollow cylinder, separated by a space of about one-eighth of an inch from its concentric casing.

From Photographs of Nebul? and Clusters Made with the Crossley Reflector by Keeler, James Edward