00:01
Okay, here i want to find f -dashed, the first differential of this function.
00:05
And here is a product.
00:08
This is u and this is v.
00:12
So to work out, f -dashed of x, use the product rule, which is u, for the words, write down u with no change, times v -dashed, differentiate ln of 8x minus 5.
00:28
And that becomes 1 over 8x minus 5.
00:33
Chain rule multiplied by 8.
00:37
Otherwise, differentiate the bracket inside.
00:42
Now, plus v, ln of 8x minus 5 times u -dash, or du by dx, and differentiate e power 7x plus 2.
00:58
I get e 7x plus 2, the exact same thing.
01:03
But again, by the chain rule, times that by 7...