00:01
Okay, so we have this differential operator, l is equal to d cubed minus 2x d squared, 2x d squared.
00:11
So if we have l of y, this is going to be equal to, so d cubed minus 2x d squared, so this is going to be d cubed, y minus 2x d squared y.
00:25
So d cubed y is the third derivative of y, and then d squared y is the second derivative of y, and then d squared y is the second derivative of.
00:31
Of y.
00:32
So for part a, we are given 2 e to the 3x.
00:36
Y of x is equal to 2 e to the 3x.
00:41
So we'll need to find the up to the third derivative of y.
00:45
So, d, y, this is going to be equal to 6e to the 3x.
00:51
Then b squared y is going to be equal to 18e to the 3x.
00:56
And then finally, the cubed y, this is going to be equal to so 3 times 2.
01:02
18 is 54, 54 e to the 3x.
01:08
So we'll start with l of y is going to be equal to 54e to the 3x and then minus 2x d squared y.
01:20
So 2x times this, okay, minus 2 times 18 is 36 and then xe to the 3x.
01:30
So that's our answer for part a.
01:36
Then for part b, we are given that y of x is equal to 3 ln of x.
01:43
So d, y, here, remember the derivative of lnx is 1 over x...