Is average velocity equal to the average of two instantaneous velocities. I had a question on a calculus exam that gave an equation to a particle moving and was told to find both the average velocity on the time interval [0,1] and the instantaneous velocity at 1. I took the derivative of the equation to find the slope and found the instantaneous velocity at 0 and at 1 and divided by 2. I was told that was incorrect by my professor because "average velocity is measured through distance". He did not explain anymore. Can anyone elaborate on why my method was incorrect.