help please 29
@Loser66
to me, the inside can be replace by \[(tan^{-1}(2)-tan^{-1}(1))+tan^{-1}(3)-tan^{-1}(2))+\cdots\]
So, we cancel the like terms. At the end, we have \(-tan^{-1}(1) +tan^{-1}(\infty)\) But \(tan^{-1}(1) = \pi/4 \) and \(tan^{-1}(\infty) = \pi/2\) So the answer should be \(\pi/4\) Let's wait for some others.
as we used to say "telescopes"
telescope series?
@Kainui
:d
Figure it out girl?
oh not yet D: i skipped it lol
@zepdrix come back online lmao
Did you not understand what Lose did?
no lol
:U
\[\rm \sum_{n=1}^{\infty}\left(Atan(n+1)-Atan(n)\right)\]Expand out the sum by inputting the n values,\[\rm =(Atan2-Atan1)+(Atan3-Atan2)+(Atan4-Atan3)+...\]
What you should notice is that a bunch of stuff is going to cancel out,\[\rm =(\cancel{Atan2}-Atan1)+(Atan3\cancel{-Atan2})+(Atan4-Atan3)+...\]because of all the subtraction, ya?
\[\rm =(\cancel{Atan2}-Atan1)+(\cancel{Atan3}\cancel{-Atan2})+(Atan4\cancel{-Atan3})+...\]
There is one term in the front that doesn't cancel out with anything. And there will also be one term in the very end that doesn't cancel with anything.
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