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Mathematics 13 Online
OpenStudy (anonymous):

Find the integral.

OpenStudy (anonymous):

zepdrix (zepdrix):

\[\large \int\limits \frac{6x+9}{4x^2+4x+5}dx\]Hmm I think we can do a `U sub`, we just have to mess around with it a bit.

OpenStudy (anonymous):

i am going to guess annoying partial fractions just a guess

OpenStudy (anonymous):

yeah, i got all mixed up so asking for help... lol

zepdrix (zepdrix):

Darn I thought that was going to work XD lol

OpenStudy (anonymous):

no, that was a bad guess on my part

OpenStudy (anonymous):

i think the u sub idea is better

zepdrix (zepdrix):

I can't quite get it to work, hmm.\[\large u=4x^2+4x+5\]\[\large du=8x+4\;dx \qquad \rightarrow \qquad du=\frac{3}{4}(6x+3)dx\]\[\large \frac{4}{3}du=(6x+9-6) \;dx\] Hmmmmm I don't think it quite works out, cause of that darn dx D:

OpenStudy (anonymous):

\[\large \int\limits \frac{6x+9}{4x^2+4x+5}dx\] \[\large \int\limits \frac{6x+3}{4x^2+4x+5}dx+\large \int\limits \frac{3}{4x^2+4x+5}dx\]\]

zepdrix (zepdrix):

Ah yes :P

OpenStudy (anonymous):

u sub for the first one, some annoying completing the square for the second

zepdrix (zepdrix):

Err +6 on top of the second one.

zepdrix (zepdrix):

Understand what's going on albie? :3

OpenStudy (anonymous):

i had something different, dont know if this is better though. took out the six at the beginning. had: \[6 \large \int\limits\limits \frac{x+\frac{ 9 }{ 6 }}{4x^2+4x+5}dx \] then added an eight

OpenStudy (anonymous):

umm

OpenStudy (anonymous):

\[\frac{ 6 }{ 8} \large \int\limits\limits\limits \frac{8x+\ 8\frac{ 9 }{ 6 }}{4x^2+4x+5}dx \]

OpenStudy (anonymous):

yea i understand... separated the equation into two fractions.

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