00:01
Now, let's solve exercise 20.
00:04
In this exercise, we want to find the derivative of the function of x equals parentheses 1 plus 2x squared, parenthesis squared plus 2x cubed.
00:24
We first multiply the pericithesis out.
00:29
It equals 1 times 4x squared plus 4x to a power 4 plus 2x cubed.
00:43
And now let's rewrite this expression using the descending power.
00:52
It equals 4 x to a power 4 plus 2x cubed plus 2x cubed plus 4.
01:00
X squared plus 1.
01:04
And according to rule 4, the derivative of the sum equals the sum of the derivative.
01:11
And hence, we need to calculate the derivative of all these four terms.
01:20
The derivative of the first term plus the derivative of the second term plus the derivative of a third term plus the derivative of a fourth term.
01:39
So according to rule 3, the derivative of this term equals a constant times the derivative of x to a power of 4...