1. Choose two values of t such that t = 3 is the mean of them. For instance:

2. Now calculate h(2) = ... and h(4) = ...

Calculate the slope between and . This slope has the same value as the instantaneous velocity at t = 3.

3. Remark: This methodonlyworks if you are dealing withparabolas

4. Try if you get the same result if you use

5. You should have got 0.