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integration help? (1 Viewer)

school4nerds

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How does

1/2 x int du/3u + 1

become:

1/3 x ln |u +1| + c ??

also, how do we know when we need the absolute value when integrating (especially with log's)??
 

deswa1

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How does

1/2 x int du/3u + 1

become:

1/3 x ln |u +1| + c ??

also, how do we know when we need the absolute value when integrating (especially with log's)??
No offence, but I think this is one of the worst examples of lack of bracketing I have ever seen in my life. Don't worry about the times symbol, enclose everything in brackets that goes together and please try reposting that.
 

Carrotsticks

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How does

1/2 x int du/3u + 1

become:

1/3 x ln |u +1| + c ??

also, how do we know when we need the absolute value when integrating (especially with log's)??


I agree that your bracketing is very poor. We can't help you if we don't know what you're saying.

Also, some people use the absolute value whereas others just use normal brackets, both are acceptable but I prefer the bracket. The only reason why people use the absolute value sign is because of the whole "If y=log(x), then x MUST be greater than 0" which I don't think is the best way to think about things because negative logarithms are defined (not in HSC Syllabus) but nonetheless still well-defined.
 

school4nerds

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yeah sorry guys, forgot to bracket properly. but yeah carrotsticks has the integration i meant. and yeah i got what you got as well, i guess the solutions are wrong then
 

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