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Mathematics 8 Online
OpenStudy (anonymous):

Did i do this right?

OpenStudy (anonymous):

\[\int\limits_{-1}^{1} (e ^{u+1})du = e^{2}-1\]

OpenStudy (unklerhaukus):

\[\int\limits_{-1}^1(e^{u+1})\text du=\frac{e^{u+1}}{u+1}\Big|_{-1}^1\]

OpenStudy (unklerhaukus):

or did you mean \[\int\limits_{-1}^1(e^{u}+1)\text du \]

OpenStudy (anonymous):

no its e^{u+1}

OpenStudy (anonymous):

e^2/2-1/0?

OpenStudy (unklerhaukus):

thats what i got, but 1/0 dosent really make sense

OpenStudy (unklerhaukus):

maybe we have to take a limit

OpenStudy (anonymous):

e^0=1?

OpenStudy (anonymous):

d/du e^{u+1} = e^{u+1} * d/du (u+1)

OpenStudy (unklerhaukus):

\[e^0 =1 \checkmark\]

OpenStudy (anonymous):

so is it not.... e^2/2-1/0?

OpenStudy (unklerhaukus):

the zero in the denominator is freaking me out a bit

OpenStudy (anonymous):

hahah yeah...

OpenStudy (unklerhaukus):

\[\frac{e^{u+1}}{u+1}\Big|_{-1}^1\]\[=\frac{e^{1+1}}{1+1}-\lim\limits_{x\rightarrow-1}\frac{e^{x+1}}{x+1}\]\[=\frac{e^{2}}{2}-\lim\limits_{x\rightarrow-1}\frac{e^{x+1}}{x+1}\]\[\stackrel{\text{l'H}}=\frac{e^{2}}{2}-\lim\limits_{x\rightarrow-1}\frac{(x+1)e^{x+1}}{1}\]

OpenStudy (anonymous):

\[\int\limits_{-1}^{1}e^{u+1} du = e^{u+1} |_{-1}^{1}\]

OpenStudy (unklerhaukus):

hmm? did you use a subsitution or something @scarydoor ?

OpenStudy (anonymous):

\[\frac{d}{du} e^{u+1} = e^{u+1} \frac{d}{du} (u+1) = e^{u+1} * 1 = e^{u+1}\]

OpenStudy (anonymous):

so e^(u+1) is an anti-derivative of e^(u+1) (forgetting about the constant...). So there's no need for the 1/(u+1). I didn't spot that at first either.

OpenStudy (anonymous):

What tipped me off, is that if you plot e^(u+1) it'll look something like: |dw:1355146202044:dw| And the area under the curve there really shouldn't involve any kind of limits.

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