Question 949897
The interval for the change on the x-axis is  {{{t-a}}}.
The G values change from {{{3t^3-5t-(3a^3-5a)}}} or {{{3t^3-5t-3a^3+5a}}}.
The average rate of change is  {{{(3t^3-5t-3a^3+5a)/(t-a)}}}.