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Mathematics 15 Online
OpenStudy (konradzuse):

Series question. NEEED HELP PLEASE!

OpenStudy (konradzuse):

\[\sum_{1}^{\infty} (\sin(8)^n\]

OpenStudy (konradzuse):

it should be a(r)^n and since sin(8) < 1 we can use a/(1-r) but for some reason it says sin(8) is both a and r... Why is that?

OpenStudy (konradzuse):

It should be sin(8)/(1-sin(8)) but apparently that's not right....

OpenStudy (konradzuse):

0.1617 :(

OpenStudy (zarkon):

\[\sum_{n=1}^{\infty}ar^{n-1}=\frac{a}{1-r}\] \[\sum_{n=1}^{\infty}(\sin(8))^n=\sum_{n=1}^{\infty}\sin(8)\times(\sin(8))^{n-1}\]

OpenStudy (konradzuse):

so sin(8) x 1?

OpenStudy (zarkon):

is the 8 in radians or degrees?

OpenStudy (zarkon):

it is \[\frac{\sin(8)}{1-\sin(8)}\]

OpenStudy (konradzuse):

I would assume degrees... But Idk doesn't say...

OpenStudy (konradzuse):

if it was radians it would have a pi right? It asks for the 4 decimal places, which would be 0.1617

OpenStudy (zarkon):

if it is in degrees then you get .16167...

OpenStudy (zarkon):

or what you have if you want 4 decimal places

OpenStudy (zarkon):

if radians you get 92.9695

OpenStudy (konradzuse):

But apparently that answer is wrong... In the practice version it says sin(3) and does it the same way, but that $ works... 0.1643 I think...

OpenStudy (konradzuse):

so what exactly are you showing in the bottom one where you say sin(8) x (sin(8)^n-1? A and R?

OpenStudy (zarkon):

then it is in the correct form \[a=\sin(8)\] and \[r=\sin(8)\]

OpenStudy (konradzuse):

how do we find that? With what I said above?

OpenStudy (zarkon):

look at my first post...match up the letters

OpenStudy (konradzuse):

yeah so sin(8) x sin(8)^n-1?

OpenStudy (konradzuse):

and yeah the radian answer worked... WHY IDK...

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