Let f be defined as follows.
y = f(x) = x2 − 5x
(a)
Find the average rate of change of y with respect to x in the following intervals.
from x = 4 to x = 5
from x = 4 to x = 4.5
from x = 4 to x = 4.1
(b)
Find the (instantaneous) rate of change of y at x = 4.