Math derivatives
posted by Marissa .
What is the derivative of:
a) cos(3x)
b) π/x
I did (a) just by following chain rule:
sin(3x)*3
so it's 3sin(3x)
Is that correct?
I'm not completely sure how to do (b). Would it just be like the derivative of 1/x? That's 1/(x^2), would it be π/(x^2) ?

Math derivatives 
drwls
Both of your answers are correct. Nice job!
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