Answer:
[tex]f'(y) = -9e^{-9y}[/tex]
Step-by-step explanation:
The given function is :
[tex]f(y) = 8 + e^{-9y}[/tex]
We need to find the value of f'(y).
[tex]f'(y)=\dfrac{d}{dy}[8+e^{-9y}][/tex]
[tex]=\dfrac{d}{dy}(8)+\dfrac{d}{dy}(e^{-9y})\\\\=0+e^{-9y}\dfrac{d}{dy}(-9y)\\\\=-9e^{-9y}[/tex]
So, the value of f'(y) is equal to [tex]-9e^{-9y}[/tex].
