You're close, but missing something.
You understand that the derivative of ln(x) is 1/x, so
you have (8-e^(-x)) in the denominator, which is the first step correctly done.
The next step is to apply the chain rule to derive the argument of log,namely
d(8-e^(-x))/dx
=(0-(-e^(-x)))
=+e^(-x))
So the final answer should be
+e^(-x))/(8-e^-x)
Another source of error is that you do not appear to use parentheses appropriately.
Even if you had given the answer as
e^-x/8-e^-x
it would be incorrect, because it means
e^-(x/8)-e^-x
properly written (especially for a computer answer), it should be:
(e^-x)/(8-e^-x)
or even
(e^(-x))/(8-e^(-x))
Find the derivative.
f(x)=ln(8-e^-x)
I got -e^-x/8-e^-x
but it was wrong.
WHAT DID I DOOOO?!
1 answer
1 answer