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try finding out the derivitive of this without using a calculator and then see if you got it right... for the people in highschool, you might get it wrong, believe it or not :D :
y= ln(-x)
answer:
1/x and not -1/x
I know this is obvious for some people..dont say this is a stupid problem, because some people including me DO get this wrong the first time :p
Hmm, it's good that.
Quite funny to see people's reaction when differentiating the following, if they're not familiar with manipulating logs:
y=ln(x)
y=ln(x^2)
y=ln(x^3)
i don't see how hard it is if you know the chain rule: y=ln(-x)
y'=d (ln(-x))/d (-x)*d(-x)/dx
y'=1/(-x)*(-1)
y'=1/x
Quote:
I know this is obvious for some people..dont say this is a stupid problem, because some people including me DO get this wrong the first time
Yeah its a common mistake amoung those just learning to differentiate. A lot of people also struggle with ln(1/x). But you generally learn all the tricks quite quickly
:D