Random Insanity Alliance Forum, Mark V
Cactuar Zone => Random lnsanity => Topic started by: Arsenal 10 on July 23, 2010, 03:30:42 am
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I can manage with most things, but seeing as calculus really isn't my strong point, I need some help.
So yeah, if someone could tell me how to work out the partial derivitives of the following function:
S = (16000-800P)A0.5R0.5
I need to know:
dS/dR =
dS/dA =
dS/dP =
How do I do it?
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Florida.
Also I think CI studies this kind stuff so flick him the question.
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Ah ok, I'll send him a PM.
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Man, it's been a long time since I did this. I am inclined to tell you that the simplest approach is right, but I don't remember for sure.
Basically, any term not related to the term you are taking the derivative of is treated as a constant. So, iirc:
S = (16000-800P)A0.5R0.5
I need to know:
dS/dR = -0.5(16000-800P)A0.5R-0.5
dS/dA = -0.5(16000-800P)A-0.5R0.5
dS/dP = -800A0.5R0.5
But like I said, it's been a very long time.
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Thanks for the help, though I don't think that is right.
I'm not sure if I need to use the product rule or something.
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Don't have time to try and work them out manually right now but these may help a tiny bit:
dS/dR = Click Here (http://www.wolframalpha.com/input/?i=d%2Fdr+%2816000-800P%29%28A^0.5%29%28R^0.5%29)
dS/dA = Click Here (http://www.wolframalpha.com/input/?i=d%2FdA+%2816000-800P%29%28A^0.5%29%28R^0.5%29)
dS/dP = Click Here (http://www.wolframalpha.com/input/?i=d%2FdP+%2816000-800P%29%28A^0.5%29%28R^0.5%29)
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Oh dear..
My mind struggles to keep up with that.
(http://www3.wolframalpha.com/Calculate/MSP/MSP35919bdbbg628bc3e19000010af7a517h9509i4?MSPStoreType=image/gif&s=3&w=480&h=89)
I don't know why the A'(R) and P'(R) are there..
In fact, I can't follow that at all. I hate calculus.
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They are not assuming the others are constant, but rather assuming that they could be a function of R.
Like I said, it's been forever.
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Oh right.
dS/dR = 0.5(16000-800P)A0.5R-0.5
dS/dA = 0.5(16000-800P)A-0.5R0.5
dS/dP = -800A0.5R0.5
Jenne, you meant your answers to be this right? As in without the negative at the front. Because when you bring down the 0.5, it was positive.
Because on second thought, I think this may be it. I can't imagine it is as hard as that calculator thing says, it shouldn't be anyway.
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Ok, I'm pretty sure I have the answers I'm looking for.
Thanks.
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Oh right.
dS/dR = 0.5(16000-800P)A0.5R-0.5
dS/dA = 0.5(16000-800P)A-0.5R0.5
dS/dP = -800A0.5R0.5
Jenne, you meant your answers to be this right? As in without the negative at the front. Because when you bring down the 0.5, it was positive.
Because on second thought, I think this may be it. I can't imagine it is as hard as that calculator thing says, it shouldn't be anyway.
yeah, that is what I meant, though I would tend to agree with the calculator. Wolfram is pretty good. I used their site to check my stuff a lot in college. Of course, we did a lot of work it Mathmatica, so it made sense to use them.
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what the fuck does any of that mean?
Jesus, I was taking college level algebra in high school, now I can't even remember how to do long division. >_>
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Arse...i can do that, ci and i both have an interest in calculus...that's about the only thing i used to like about grade 12 math, so i did it even after school, just for kicks.
If you need more help in calculus, pm me if ci isn't there.
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Arse...i can do that, ci and i both have an interest in calculus...that's about the only thing i used to like about grade 12 math, so i did it even after school, just for kicks.
If you need more help in calculus, pm me if ci isn't there.
Oh cool. I did send CI a PM.. But thanks, I'll probably use you :P
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Sorry I should probably respond to this now. I was going to post something the morning after you send me the message, but Jenne already posted the right answers.
I think you need to go back over your old calculus 1 material. Most of calculus 3 is teaching calculus 1 in more than one variable.
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Oh, my father is an accountant... so... uh... that means nothing.
I'm like, math illiterate or something.