- #1
PeterPumpkin
- 34
- 0
I wanted to differentiate (cos(x))^x
Applying the chain rule I got -x(sinx)(cosx)^(x-1)
But when I go to WolframAlpha, they show
d/dx(cos^x(x)) = cos^x(x) (log(cos(x))-x tan(x))
Why the extra term? Why doesn't the simple chain rule apply?
I have got strange results from WolframAlpha before
eg try typing (-1)^(1/3)
You don't get -1 as a root.
Applying the chain rule I got -x(sinx)(cosx)^(x-1)
But when I go to WolframAlpha, they show
d/dx(cos^x(x)) = cos^x(x) (log(cos(x))-x tan(x))
Why the extra term? Why doesn't the simple chain rule apply?
I have got strange results from WolframAlpha before
eg try typing (-1)^(1/3)
You don't get -1 as a root.