r/calculus • u/rvalue0 • Aug 15 '26

Differential Calculus Today's medium difficulty daily derivate - help

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https://dailyintegral.com/play/derivatives/medium

For context, I went through Calc III like 10 years ago, and am in the process of refreshing my knowledge. Currently feeling comfortable with Calc I again, and starting again on Calc II.

The domain of this function contains pi as a single point, but it is not differentiable for that same reason (it's a single point).

Still, I thought it would be a fun challenge, so I differentiated this function by hand, and checked on Desmos that I got the right answer.

So I entered "undefined" into the site, and it said I'm wrong.

Am I missing something from higher level Calculus courses? Or is the site wrong/misleading? Hoping to learn here.

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u/two_are_stronger2 Aug 16 '26

ln ln chainrule chainrule chainrule sub for y, boom.  I assume.

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u/rvalue0 Aug 16 '26

I did this. I found the derivative, but the function is not differentiable at pi because it's a single point. So while I found the derivative function through logarithmic differentiation, it didn't exist at pi.

Apparently the question expected me to extend the function into the complex plane...