For every change in x, y changes 2/pi.
In order to find this we first need to evaluate the expression at the intervals.
x = 0
f(x) = 1 + sinx
f(0) = 1 + sin0
f(0) = 1 + 0
f(0) = 0
x = pi/2
f(x) = 1 + sinx
f(pi/2) = 1 + sin(pi/2)
f(pi/2) = 1 + 1
f(pi/2) = 2
So the total change in y is 1. So we divide that by how much x has changed in that interval to find the average rate of change.
1 / (pi/2) = 2/pi
