00:01
Okay, so let's use our quotient rule to find the following derivative.
00:04
So we have, let's label our numerator as u and our denominator as b.
00:11
So we have y prime that's equal to u prime, which is negative to x plus 8 times rb.
00:25
And then minus v prime, that's x times ru, all over v squared.
00:37
4 x squared and minus 5 to the power of 2.
00:40
Okay, now let's expand each term.
00:43
So i'll expand this in green.
00:46
So we have negative 2 times 4, so that's negative 8, x to the power of 3, plus 5 times 2 is 10x, plus 8 times 4.
01:03
That's 32 times x to the power of 2, and then minus 8 times 5, which is 40...