Let f be continuous on [2,6] and let fˉ denote its average value on this interval. Which statement is always true?
a) The area under y=f(x) from 2 to 6 equals 4fˉ2.
b) There exists at least one c∈(2,6) such that f(c)=fˉ.
c) The point (4,fˉ) lies on the graph of f.
d) fˉ is always greater than f(2) and less than f(6).