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Derivative help!

Can someone help? How do I go about getting the derivative of. Y=2/x^4 ???
Reply 1
Avatar for xiyangliu
xiyangliu
2
Original post by kenny629
Can someone help? How do I go about getting the derivative of. Y=2/x^4 ???


Take y = 2 * x^-4.


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Original post by kenny629
Can someone help? How do I go about getting the derivative of. Y=2/x^4 ???


Well, you can rewrite it as y=2x−4y=2x^{-4}

see it now?
Reply 3
Avatar for xiyangliu
xiyangliu
2
And go from there


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Reply 4
Avatar for panda1093
panda1093
13
(...)
(edited 11 years ago)
Reply 5
Avatar for xiyangliu
xiyangliu
2
Original post by panda1093
y= 2* (X)^-4 so Y=2* (-4)X^-5 so Y=-8/X^5
I hope you understand it. You just need to understand that 1/x^a= x^-a and of course you need to keep in mind the rule derivative of x^a= aX^(a-1)


Spoiler alert :biggrin:


This was posted from The Student Room's iPhone/iPad App
Original post by panda1093
y= 2* (X)^-4 so Y=2* (-4)X^-5 so Y=-8/X^5
I hope you understand it. You just need to understand that 1/x^a= x^-a and of course you need to keep in mind the rule derivative of x^a= aX^(a-1)


It's really messy not using LaTeX - you'll probably just confuse the OP
Reply 7
Avatar for Hasufel
Hasufel
16
1st time using lateX so here goes:

write it as: y=2x−4y=2x^{-4}

and use the power rule for derive`s
Reply 8
Avatar for DFranklin
DFranklin
18
Original post by panda1093
I just wanted to help and I got negged twice, any reason?
Probably because the Guide to Posting says not to post full solutiions, and it's particularly rude to do so after other people have started to help. (Although I didn't actually neg you).

Posting full solutions is actually against the rules and you can be warned if you persist in doing it.
Reply 9
Avatar for kenny629
kenny629
OP
Thankyou for all of your replies!

Yes i was not looking for an answer, just a starting point, but see the process now. Sometimes the simplest ones seem difficult as my brain goes straight to the chain rule etc when it doesnt require it!
Excellent forum!

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