The function f is given by f (x) = 3x^2+1. What is the average value of f over the closed interval [1,3]?

You can find the answer using the equation (f (b) - f (a)) / (b-a). For this problem, a=1 and b=3.

Then, plug in the numbers and solve:

[ (3 (3) ^2+1) - (3 (1) ^2+1) ] / (3-1)

= (28-4) / 2

=12