Chain Rule Help

dalasTR

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Sep 13, 2009
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14
Find the derivative of the function
I am having a few issues with these problems. If I can get help with how to do the first one or two from each set I'd like to try the rest. My work is below.[attachment=1:2ie5dwjy]pic1.jpg[/attachment:2ie5dwjy][attachment=0:2ie5dwjy]pic2.jpg[/attachment:2ie5dwjy]

Any help is GREATLY appreciated and needed.
 

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I'll do one for you to get you started.

f(v) = (12v1+v)3\displaystyle f(v) \ = \ \bigg(\frac{1-2v}{1+v}\bigg)^{3}

f  (v) = 3(12v1+v)2((1+v)(2)(12v)(1)(1+v)2)\displaystyle f \ ' \ (v) \ = \ 3\bigg(\frac{1-2v}{1+v}\bigg)^{2}\bigg(\frac{(1+v)(-2)-(1-2v)(1)}{(1+v)^{2}}\bigg)

= 3(12v)2(1+v)2(3(1+v)2)\displaystyle = \ 3\frac{(1-2v)^{2}}{(1+v)^{2}}\bigg(\frac{-3}{(1+v)^{2}}\bigg)

= 9(12v)2(1+v)4\displaystyle = \ \frac{-9(1-2v)^{2}}{(1+v)^{4}}
 
Thanks! I was able to solve the third one in the first set with your help. However, I am still stuck on the first two... I do the product rule correct?
 
Nevermind I figured them out! :) Thank you.

Any help on the second set ofquestions?
 
The second one in the last set can be rewritten:

cos(v)csc(v)=sin(v)cos(v)\displaystyle \frac{cos(v)}{csc(v)}=sin(v)cos(v)

Now, just use the product rule.
 
g(v) = cos(v)csc(v) = cos(v)11sin(v) = cos(v)sin(v)\displaystyle g(v) \ = \ \frac{cos(v)}{csc(v)} \ = \ \frac{\frac{cos(v)}{1}}{\frac{1}{sin(v)}} \ = \ cos(v)sin(v)

Now,g  (v) = [cos(v)cos(v)]+[sin(v)(sin(v)] = cos2(v)sin2(v).\displaystyle Now, g \ ' \ (v ) \ = \ [cos(v)cos(v)]+[sin(v)(-sin(v)] \ = \ cos^{2}(v)-sin^{2}(v).
 
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