Define instantancous speed. What does speedometer measure ?

Explanation

The speed of an object at any particular instant of time or at a particular point of its path is called the instantaneous speed of the object If `Delta x` is distance travelled is small intervalled in small interval `Delta t,` then
Instantaneous speed, `v= Lim _(Delta t to 0) (Delta x)/( Delta t) = (dx)/(dt).`
The speedometer of an outomobile measures its instantaneous speed.