# Math question

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• 09-30-2002
BMJ
Math question
Er... verify something for me guys; Is the derivative of
Code:

`sin(cos(x))`
equal to
Code:

`-cos(cos(x))sin(x)`
:confused:
• 09-30-2002
Govtcheez
That's not what I got - I got
sin(-sin(x)) * cos(cos(x))

I could be wrong, though.
• 09-30-2002
BMJ
Where did that extra sine come from?
• 09-30-2002
Govtcheez
Chain rule.
• 09-30-2002
BMJ
Code:

`f(x) = sin(cos(x))`
Code:

`f'(x) = cos(cos(x)) * (-sin(x)) * (1)`
Right?
• 09-30-2002
Govtcheez
Um... Maybe. Like I said, I could be (and likely am) wrong...

Heh, 3 years of calc, and I can't remember a damn thing. Thank you, beer!
• 09-30-2002
Govtcheez
The answer I got from people that are better at this than me was -sin(x) * cos(cos(x)), so the same thing that you got.

Guess it's time to dig out that calc book again.
• 09-30-2002
BMJ
I just want to make sure I am remembering this stuff right so that I don't mess my entire week up as I go back trying to figure out what's wrong only to find it's this stuff :rolleyes:
• 09-30-2002
BMJ
Ok thanks Govtcheez! :)
• 09-30-2002
ober
working on... finding... Maple...

ok... I can't locate a free download of it anymore, but it's useful for checking your derivatives/integrals... sorry... you could look around for a copy of it tho.
• 09-30-2002
BMJ
I've never heard of it... does it work well?
• 09-30-2002
Govtcheez
ONce you figure it out, it's helpful. I never got the hang of it, though.
• 09-30-2002
BMJ
Hmmm... maybe I should write something to calculate derivative expressions like a TI-89 or Maple does :)
• 09-30-2002
ober
yeah, there's definately a learning curve, but when you can type in an equation and it spits out what you want.... you just can't beat it.
• 09-30-2002
dbaryl