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#1 2008-11-23 20:45:33

Angel Rox
Member
Registered: 2008-11-10
Posts: 15

Help me out with this .... its really urgent

If f(4)=3 & f'(4)=-5, find g'(4). where g(x) = √x  f(x)?

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#2 2008-11-23 21:26:28

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: Help me out with this .... its really urgent

Using the product rule, g'(x) = √x f'(x) + (1/2√x)f(x).
∴ g'(4) = 2*-5 + (1/4)*3 = -9 1/4


Why did the vector cross the road?
It wanted to be normal.

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#3 2008-11-23 21:44:08

Angel Rox
Member
Registered: 2008-11-10
Posts: 15

Re: Help me out with this .... its really urgent

Thanks .. Thanks Alot

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