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# Help with differentiating this equation. watch

1. I tried quotient rule and regular rule but seem to get the wrong answer. Please explain how you did it.

2. (Original post by Jyashi)
I tried quotient rule and regular rule but seem to get the wrong answer. Please explain how you did it.

ddx[4x2+5−xx]
I can't understand the expression
3. Do you mean 4x^2 + 5 + x^x ?
4. Sorry guys just updated with question
5. (Original post by zetamcfc)
I can't understand the expression
Just updated the question
6. (Original post by Jyashi)
Just updated the question
What is your problem with this? Differentiate the first term normally. Then quotient rule the second.
7. (Original post by Jyashi)
Just updated the question
No need for quotient rule:
8. What you wrote was nothing like the question but you'd need to rearrange it so the fraction is an integer, 4x^2+ (5-x)(x^-1)
9. (Original post by joostan)
No need for quotient rule:
Not really with it lol
10. I tried using chain rule and quotient rule but the answer that i need is 8x-5/x^2 which im not getting
11. (Original post by Jyashi)
I tried using chain rule and quotient rule but the answer that i need is 8x-5/x^2 which im not getting
Instead of telling us what you're doing, why don't you post out your working instead so we can see what you're actually doing?
12. (Original post by Zacken)
Instead of telling us what you're doing, why don't you post out your working instead so we can see what you're actually doing?
Its fine i managed to resolve it. But surprised that i got different answers using the chain rule and quotient rule.
13. (Original post by Jyashi)
Its fine i managed to resolve it. But surprised that i got different answers using the chain rule and quotient rule.
They're not different answers if you did both procedures correctly.
14. (Original post by Zacken)
They're not different answers if you did both procedures correctly.
Oh i am sure i messed up somewhere there. On a side note can you tell me what is the implicit derivative of ln(y) ? Do you treat y as a constant which would mean derivative of y will be 0 but then do you do 0 dy÷dx?
15. (Original post by Jyashi)
Oh i am sure i messed up somewhere there. On a side note can you tell me what is the implicit derivative of ln(y) ? Do you treat y as a constant which would mean derivative of y will be 0 but then do you do 0 dy÷dx?
It is (dy/dx)/y. Differentiating the logarithm of somethins is the derivative of something over the something. In this case the something is y, so d/dx(y) = dy/dx.

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Updated: March 19, 2016
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