The function (x) = x⁴ - 18x² + 12 has a derivalive of ' (x) = 4x³ - 36x = 4x(x²- 9). Determine the x - values that should be evaluated in (x) to find the extreme values of the function on the interval -1, 6 according to the extreme value finclion.
a. x = - 2
b. x = 5
c. x = 1
d. x = 3
e. x = - 1
f. x = 0
g. x = - 3
h. x = 4
i. x = 6
j. x = 2