00:01
All righty, so we've been asked to find the third order derivative of this function right here.
00:05
So we're going to start by taking our first order derivative, our first order derivative, y prime, will be cosine of x cubed times.
00:17
We're going to use our chain rule.
00:20
The derivative of x cubed is 3x squared.
00:24
And that is our first derivative.
00:26
Our second order derivative, y double prime.
00:30
We're going to use the product rule here.
00:32
So the derivative of the first is negative sign x cubed times the derivative of the inside, 3x squared, times our second term, 3x squared again.
00:53
Then we're going to add our first term, cosine of x cubed, times the derivative of our second term, which will just be 6x.
01:09
So if i put this all together, we'll rewrite y double prime.
01:16
That'll come out to be negative sign x cubed, all multiplied by 9x to the 4 plus cosine x cubed times 6x.
01:37
And for our final order derivative, we're going to have to do two product rules.
01:44
That's a y triple prime.
01:46
We're going to start with our first round of product rule, so put a bracket here.
01:54
Negative cosine of the inside.
02:00
We use our chain rule.
02:02
Take the derivative of x cubed, which is 3x squared.
02:06
Then we will take our just second term as usual, 9x to the 4.
02:13
Then we will add, or i subtract since the sign is negative, our first term, times...