00:01
Hi there, so for this problem we are given that the surface area is given by this expression that we are given.
00:08
So then we are given that its height age for this person at the moment that we want to calculate this is 170 centimeters and the weight for this person is 60 kilograms.
00:25
Okay, so the question is to use differentials to estimate how much our surface area should.
00:31
Changes after weight decreases by a factor.
00:36
So we're gonna, the value for delta x.
00:42
Well, delta y, since it is decreasing, this should be negative and that will be minus two.
00:52
Okay, so let's see what value we obtain by using differentials.
00:59
So first of all, we know that, and we can calculate the how much surface area change as delta x.
01:10
By just this is the partial derivative of s with respect to the weight because the height, i'm assuming that is a constant.
01:23
Okay? and then this times the change in the weight.
01:31
First we're going to calculate the partial derivative of this with respect to the weight.
01:37
So we just derivate the term that is related to the weight, leaving the other as a constant.
01:45
Then we will have for this that this is 0 .0, 22, 35.
01:55
This times 0 .51, 456, and then this times the height elevated to 0 .56...