**
Acceleration Vector
** -
A vector that represents the instantaneous acceleration of a particle moving along a
parametric curve

(*x*(*t*), *y*(*t*))
; in coordinates, the

*acceleration vector* is

**
Parametric Curve
** -
A curve consisting of the points
(*x*(*t*), *y*(*t*))
, where
*t*
varies over
an interval or over the set of real numbers.

**
Polar Curve
** -
The graph of a function in polar coordinates, i.e. the points
[*r*(*θ*), *θ*]
for all
*θ*
in the domain of the function
*r*(*θ*)
.

**
Velocity Vector
** -
A vector that represents the instantaneous velocity of a particle moving along a
parametric curve

(*x*(*t*), *y*(*t*))
; in coordinates the

*velocity vector* is