00:01
We are to show that this function satisfies rolla's theorem and then find the c values that make it true.
00:08
Since we are taking the cube root and then the and the other one is taking the two -thirds power, we can fill any x value in because we can take the cube root of all positives and negatives.
00:22
So first we will say that f of x is differentiable on the open interval, 0 to 8.
00:33
Also continuous on the interval, closed interval 0 to 8.
00:42
To back up the fact that it is differentiable, let's look at the derivative.
00:47
Our derivative would be two -thirds, x to the negative one -third, minus two -thirds x to the negative two -thirds.
00:59
We could rewrite that as two over three cube root x minus two over three cube root x squared which we could combine into a single denominator of three cube root x squared first fraction we multiplied top and bottom by the cube root of x and that's what we get now that is non -differential it's zero but that's okay just has to be differentiable on the open interval under the mean value theorem, that derivative at c, which would be two, cube root x minus two, actually two cube root c minus two, over three cube root c squared, must equal zero at at least one point...