# Definition of *radius vector* in English:

## radius vector

Line breaks: ra¦dius vec¦tor### noun

*Mathematics*

1A line of variable length drawn from a fixed origin to a curve.

More example sentences

- When Archimedes defines a spiral, he gives fundamental properties connecting the length of the radius vector with the angles through which it has revolved.
- In fact, from the point P which is at distance d from the origin measured along a radius vector, the distance from P to the pole is d sec b.
- Three days later he wrote to Le Verrier asking the same question about the radius vector as he had asked Adams.

1.1

*Astronomy*A line of variable length joining a satellite or other celestial object to its primary.More example sentences

- In the second law, Kepler used the idea of radius vector, and stated that the radius vector from the sun to a planet sweeps out equal areas in equal intervals of time.
- The radius vector is shortest when the planet is at perihelion and longest at aphelion.
- The radius vector from the sun to a planet sweeps over equal areas in equal times.

## Definition of **radius vector** in:

- The US English dictionary