00:01
We are asked to find the second derivative of x, y, to the fourth equals five.
00:05
And the second derivative is the derivative of the derivative.
00:08
So i think it makes sense just to get right into doing the product rule where you leave alone.
00:14
Take the derivative.
00:16
And the derivative, anytime you take the derivative of y, you have to write out d, y, d, y, d, y, d, x.
00:21
Plus, now take the derivative of x, which is one, and leave y to the fourth alone.
00:27
And then don't forget the derivative of a constant 5 is equal to 0.
00:32
So from here, you still need to solve for dy to x.
00:36
And what i would do is just subtract the y to the fourth over, and then you can divide by 4xy cubed.
00:44
And for the record, to make this easier, is you can divide out three of those ys, so you're left with negative y over 4x.
00:56
So now we're ready to do...