
William W. answered 07/14/23
Experienced Tutor and Retired Engineer
(1/(3-0))•0∫3 x3 dx = (1/3)(1/4)x4 evaluated between 0 and 3 = (1/12)(3)4 - (1/12)(0)4 = 81/12 = 27/4
To find the "c" value where f(c) = 27/4:
27/4 = x3
x = cuberoot(27/4) = 3/cuberoot(4) = 3•cuberoot(2)/cuberoot(8) = 3cuberoot(2)/2
So c = 3cuberoot(2)/2
Another way to say this is that 3cuberoot(2)/2 is the average value of f(x) = x3 between 0 and 3