http://tutorial.math.lamar.edu/classes/calcII/IntegrationByParts_files/eq0020M.gif I wanna know how this has done Thanks
no actually it ha to integration by parts
Integration by parts! :) Let f=x and g'=e^(6x) => f'=1 g=e^(6x)/6
\[\int\limits_{}^{}fg' dx=fg-\int\limits_{}^{}f'gdx\]
plug it in! :)
i got the answer but I don't know how it has done
I don't know how to do the last part of this problem
\[x \cdot \frac{e^{6x}}{6}-\int\limits_{}^{}1 \cdot \frac{e^{6x}}{6} dx\] so do you understand this part?
all i did was plug in
yeah i did but i don't know how they got 11 and 7
\[\frac{xe^{6x}}{6}-\frac{1}{6}\int\limits_{}^{}e^{6x} dx=\frac{xe^{6x}}{6}-\frac{1}{6} \cdot \frac{1}{6} e^{6x}+C\]
so you are actually find with the integrating then you are having trouble plugin and the limits and simplifying?
fine not find
i got same your answer but I have different answer in this site
\[\int\limits_{-1}^{2}xe^{6x} dx=[\frac{xe^{6x}}{6}-\frac{1}{36}e^{6x}]_{-1}^{2}\]
\[=[\frac{2e^{6(2)}}{6}-\frac{e^{6(2)}}{36}]-[\frac{-1e^{6(-1)}}{6}-\frac{e^{6(-1)}}{36}]\]
\[=\frac{1e^{12}}{3}-\frac{e^{12}}{36}+\frac{e^{-6}}{6}+\frac{e^{-6}}{36}\]
\[=\frac{12-1}{36}e^{12}+\frac{6+36}{36}e^{-6} \] \[=\frac{11}{36}e^{12}+\frac{42}{36}e^{-6}=\frac{11}{36}e^{12}+\frac{7}{6}e^{-6}\]
Thank you very much Myininaya Can you see the answer ?
oh i see where i made a mistake
do you see my mistake?
so we have this \[=[\frac{2e^{6(2)}}{6}-\frac{e^{6(2)}}{36}]-[\frac{-1e^{6(-1)}}{6}-\frac{e^{6(-1)}}{36}] \]
\[=\frac{12-1}{36}e^{12}-\frac{-6-1}{36}e^{-6}\]
there we go
lol i wrote 1/36 as 36/36 above thats why it came out wrong the first try
yeah that make sense but how did you get 12
common denomaintor?
\[\frac{2}{6} \cdot \frac{6}{6}=\frac{12}{36}\]
yeah that make sense to me You help me a lot I really thank you so much that was very helpful to me
np
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