If dx denotes the change in position of an object and dt denotes the corresponding time interval, then instantaneous velocity is given by:

Explanation:

Remember that instantaneous velocity is just a measure to know the velocity that any object has at any point given in time, so we just need to know the distance it has travel, which would be the change in position, and the time it took that change in position to occurr, this means distance by time, so we just divide dx by dt and we have the solution for instantaneous velocity.