00:01
So this question wants to find the interval which the function is increasing and decreasing.
00:06
So let's look at the function.
00:12
So what i'm going to do, i'm going to distribute out the x to the one -third so i could take the derivative easier.
00:20
And now let's take the derivative.
00:23
I'm going to be four -thirds x to the one -third plus eight over three -x to the two -thirds.
00:34
Let's just rewrite this with a common denominator.
00:37
So i'm going to multiply the other side by x to the 2 thirds.
00:40
So this becomes 4x plus 8 over 3x to 2 thirds.
00:46
I'm going to find my critical numbers.
00:48
So i'm going to set the top equal to 0 and solve.
00:50
We'll get negative 2.
00:51
So at the bottom equal to 0 and solve, i get 0.
00:55
So let's make my chart.
00:57
Negative affinity to negative 2.
01:01
Negative 2 to 0...