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# C4 Integration Problem watch

1. For , should we integrate it to ln|1+x| or ln|2+2x|??

2. (Original post by mystreet091234)
For , should we integrate it to ln|1+x| or ln|2+2x|??

The former:

3. The second one.
4. (Original post by Zacken)
The former:

Where does dx come from??

THANKS!!
5. (Original post by mystreet091234)
Where does dx come from??

THANKS!!
You're integrating with respect to x.
6. (Original post by mystreet091234)
For , should we integrate it to ln|1+x| or ln|2+2x|??

Do note that .

Always try checking whether the denominator differentiates to the numerator. Taking out common factors might also help in certain cases.

Edit: it's equivalent, my apologies
7. (Original post by aymanzayedmannan)
Do note that . Your second result does not satisfy this, which is why it's incorrect.

Always try checking whether the denominator differentiates to the numerator. Taking out common factors might also help in certain cases.
But when we let y=ln|2+2x|

So why is it wrong??
8. (Original post by ri916)
The second one.
Don't
9. (Original post by mystreet091234)
But when we let y=ln|2+2x|

So why is it wrong??

Where , apologies.
10. (Original post by Zacken)

Where , apologies.
Yeah we had this problem in class. You can have any constant factor in the log, right? As long as it gives a +ve result
11. (Original post by Student403)
Yeah we had this problem in class. You can have any constant factor in the log, right? As long as it gives a +ve result
Yep.
12. Million thanks to you all

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