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# Please need help with C4 and logs watch

1. right i have dont most of the question and i also have the answer sheet but when i try to work out how they have done it, i am completely lost

after integrating i got this with values for 'u' as '1/2 and 0'

[ln|1 + u| − 3 ln|1 − u| + 2 ln|2 − u|]

= (ln 3/2− 3 ln 1/2 + 2 ln 3/2) − (0 + 0 + 2 ln 2)
= 3 ln 3/2 + 3 ln 2 − 2 ln 2
= 3 ln 3 − 3 ln 2 + ln 2
= 3 ln 3 − 2 ln 2

i am lost after the second stage with simplifying them... its probably quite obvious but please could anyone clear this up for me??

Thanks!!
2. = ln(3/2) - 3ln(1/2) + 2ln(3/2) - 2ln(2)
= ln(3) - ln(2) - (3ln(1) - 3ln(2)) + 2ln(3) - 2ln(2) - 2ln(2)
= ln(3) - ln(2) + - 0 + 3ln(2) + 2ln(3) - 2ln(2) - 2ln(2)
= 3ln(3) - 2ln(2)

then to simplify it further, continue using
ln(a) - ln(b) = ln(a/b)

and then at the end also use

a ln(b) = ln(b^a)

hope that makes some vague sort of sense
3. (Original post by lggodd)
right i have dont most of the question and i also have the answer sheet but when i try to work out how they have done it, i am completely lost

after integrating i got this with values for 'u' as '1/2 and 0'

[ln|1 + u| − 3 ln|1 − u| + 2 ln|2 − u|]

= (ln 3/2− 3 ln 1/2 + 2 ln 3/2) − (0 + 0 + 2 ln 2)
= 3 ln 3/2 + 3 ln 2 − 2 ln 2
= 3 ln 3 − 3 ln 2 + ln 2
= 3 ln 3 − 2 ln 2

i am lost after the second stage with simplifying them... its probably quite obvious but please could anyone clear this up for me??

Thanks!!

Put them together to get a single log.
4. C4 and logs?
You're not planing on blowing up the trees are ye?
5. Thanks everyone, it has cleared up how they simplified it!

Thank god for that, I'm getting some sleep before the exam I think :P
6. (Original post by Fatal_Microbes)
C4 and logs?
You're not planing on blowing up the trees are ye?

haha i wish i could just blow up Core4 Maths in genaral...
7. (Original post by didgeridoo12uk)
= ln(3/2) - 3ln(1/2) + 2ln(3/2) - 2ln(2)
= ln(3) - ln(2) - (3ln(1) - 3ln(2)) + 2ln(3) - 2ln(2) - 2ln(2)
= ln(3) - ln(2) + - 0 + 3ln(2) + 2ln(3) - 2ln(2) - 2ln(2)
= 3ln(3) - 2ln(2)

then to simplify it further, continue using
ln(a) - ln(b) = ln(a/b)

and then at the end also use

a ln(b) = ln(b^a)

hope that makes some vague sort of sense
awesome help thanks

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