00:01
So we are given v is equal to e to the power of 9x e to the power of y.
00:08
So we need to find out all the second partial derivatives.
00:11
So let's start with vx first.
00:14
So vx means partially differentiating with respect to x.
00:18
So differentiation of e power x is the same which is 9x e power of y.
00:22
Now you will be differentiating this function that is x into e power of y where y will be treated as constant.
00:29
So 9 e power y will be written as it is and the differentiation of x will be 1.
00:35
So thus the value of vx has come out to be 9 e to the power of y in multiplication with e to the power of 9x e power of y.
00:48
Now let's differentiate with respect to x again.
00:51
So vxx over here will be equals to because y is constant.
00:55
So 9 e power of y will be written as it is outside the bracket and then you can just differentiate this e power of 9x e power y again.
01:04
So e power 9x e power of y is the same.
01:07
Differentiation of 9x e power y again y will be treated as constant.
01:12
9 is constant e power y is constant and differentiation of x with respect to x will be 1.
01:18
So thus you will be left with vxx which is equal to 9 times 9 is 81 and this is 81 e power y same base.
01:27
So the powers are added.
01:28
So this is 2y e power of 9x e power of y.
01:33
So this is vxx.
01:34
Now let's just try to differentiate equation 1 with respect to y.
01:39
So x will be treated as constant.
01:41
So this is 9x e power of y.
01:44
So if x is written as constant, so 9x will be written as it is and the differentiation of e power y will be e power y.
01:51
So you get the value of vy as 9x e power of y e power of 9x e power of y.
02:00
Now let's differentiate this equation again with respect to y.
02:04
X is constant.
02:05
So 9x is written as it is and in these two functions of x treat e power y as the first function.
02:12
So e power y is the first function differentiation of e power of 9x e power of y will be the same and x will be treated as constant.
02:21
So 9x is constant and differentiation of e power y is e power y.
02:25
Then you write plus of because now you're taking e power of 9x e power y.
02:30
That is the second function differentiation of the first.
02:33
So e power y is e power y.
02:35
So thus you can simply write vyy as...