How do you differentiate #f(x)=cot(3x) # using the chain rule?
1 Answer
Feb 9, 2016
Explanation:
First, I assume you know that the derivative of
We substitute
Therefore,
#frac{du}{dx} = 3# .
Now we use the chain rule.
#frac{d}{dx}(cot(3x)) = frac{d}{dx}(cot(u))#
#= frac{d}{du}(cot(u))*frac{du}{dx}#
# = -csc^2(u) * 3#
#= -3csc^2(3x)#
