Find the critical points and the interval on which the given function is increasing or decreasing, and apply the First Derivative Test to each critical point. Let; f(x)=(4/4)x^4 + (8/3)x^3 + (-4/2)x^2 - 8x

There are three critical points. If we call them C1, C2, C3 and C1 is less than C2 which is less than C3

C1=

C2=

C3=

These three critical give us four intervals.

The left-most interval is _______, and on this interval f is decreasing while f' is negative.

The next interval (going left to right) is _______. On this interval f is increasing while is f' is positive.

Next is the interval _______. On this interval f is decreasing while f' is negative.

Finally, the right-most interval is _______. On this interval f is increasing while f' is positive.

Please fill in the blanks above.