00:01
The question, we're given a function for average speed.
00:02
We need to take its derivative.
00:03
Our first step is to put this into a form that we can take the derivative of.
00:07
So we'll do that with a negative exponent.
00:09
We're going to bring that x out of the denominator into the numerator by making the exponent negative.
00:15
Now we compute the derivative, the x, the a.
00:18
We're going to multiply this exponent in front.
00:22
So 26 .5 times negative .45 should give us negative 11.
00:33
11 .925, and then we'll drop that exponent down by 1.
00:38
So negative 0 .45 minus 1, negative 1 .45.
00:45
Okay? we need this when x equals 0 .25 and when x equals 2.
00:51
So we'll just do that on the calculator.
00:54
We're just substituting in...