Re: please check my work
Hello, ladyazpy!
Assuming that the second problem is: \(\displaystyle \L\:f(x)\;=\;\frac{100}{2\,+\,9e^{3x}}\)
. . we have: \(\displaystyle \L\:f(x) \;=\;100\left(2\,+\,9e^{3x}\right)^{-1}\)
Then: \(\displaystyle \L\:f'(x) \;=\;-100\left(2\,+\,9e^{3x}\right)^{-2}\cdot\,9e^{3x}\,\cdot\,3 \;=\;\frac{-2700e^{3x}}{(2\,+\,9e^{3x})^2}\)