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# Quotient rule? Watch

1. Asked to differentiate this function:

Used quotient rule but I don't know why the answer I've got which is right is different to how the answer is given, don't know what method they have used?
The answer given is like this:

Then simplified to:

Please can someone explain to me how they have split it into two fractions and how it is simplified? I know it's really easy but my mind is just not working well right now.
Thanks!
2. (Original post by xCBRx)

Used quotient rule but I don't know why the answer I've got which is right is different to how the answer is given, don't know what method they have used?
The answer given is like this:

Then simplified to:

Please can someone explain to me how they have split it into two fractions and how it is simplified? I know it's really easy but my mind is just not working well right now.
Thanks!
they are using this law: (a + b)/c = a/c + b/c
And then they simplify which is why the "c" in the answer is different in both parts
3. (Original post by R3L4Y)
they are using this law: (a + b)/c = a/c + b/c
And then they simplify which is why the "c" in the answer is different in both parts
Thanks! Now I understand the first part but I still don't get the final answer.
4. (Original post by xCBRx)
Thanks! Now I understand the first part but I still don't get the final answer.
hahha I kno...I was lookin at it just now..and I'm just as stuck as u atm. I know they put them back together and multiply out a part of it..but...still cant manipulate it round to give me that answer
5. (Original post by R3L4Y)
hahha I kno...I was lookin at it just now..and I'm just as stuck as u atm. I know they put them back together and multiply out a part of it..but...still cant manipulate it round to give me that answer
got it..yeh..you just have to get common factor (1 +x^2)^5 and then factorize and multiply out "the" bracket and then you get 12x(1+x^2)^5*(1-x) as ur numerator
6. (Original post by R3L4Y)
hahha I kno...I was lookin at it just now..and I'm just as stuck as u atm. I know they put them back together and multiply out a part of it..but...still cant manipulate it round to give me that answer
Ah well, at least you helped me with the first part, I thought they used another method to differentiate that we hadn't learned and I was really confused.
7. (Original post by R3L4Y)
got it..yeh..you just have to get common factor (1 +x^2)^5 and then factorize and multiply out "the" bracket and then you get 12x(1+x^2)^5*(1-x) as ur numerator
OK thanks! I haven't fully worked that out but I understand what you mean.

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Updated: December 11, 2010
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