Describe how to determine the average rate of change between x = 1 and x = 3 for the function f(x) = 3x^3+ 1. Include the average rate of change in your answer.

Astudent draws two parabolas on graph paper. both parabolas cross the x-axis at (–4, 0) and (6, 0). the y-intercept of the first parabola is (0, –12). the y-intercept of the second parabola is (0, –24). what is the positive difference between the a values for the two functions that describe the parabolas? write your answer as a decimal rounded to the nearest tenth