Ask your own question, for FREE!
Mathematics 16 Online
OpenStudy (babynini):

Really quick help with ln and integrals!

OpenStudy (babynini):

\[\int\limits_{1}^{2}\frac{ dt }{ 8-3t }\]

OpenStudy (babynini):

so using the ln(x)=1/x then I would just get ln(8-3t) evaluated at 1,2 but that doesn't work

OpenStudy (babynini):

@rvc @inkyvoyd

OpenStudy (babynini):

I end up with something like ln(2/5) when it's meant to be (1/3)ln(5/2)

OpenStudy (babynini):

Oh I figured it out \[u=8-3t\]\[du=-3dt = \frac{ du }{ -3 }\]\[\frac{ -1 }{ 3 }\int\limits_{1}^{2}\frac{ du }{ u }\]\[\frac{ 1 }{ 3 }\int\limits_{2}^{1}\frac{ du }{ u }\]\[\frac{ 1 }{ 3 }\ln(u)|^1_2\]\[\frac{ 1 }{ 3 }\ln \frac{ 5 }{ 2 }\]

ganeshie8 (ganeshie8):

Nice :)

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!