Series Proof Help: Proving |ln 2| & |sin x|

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(1) Show that |ln 2 - ƩNn=1 ((-1)n-1)(1/n)| ≤ 1/(N+1)
(2) Show that |sin x - ƩNn=0 ((-1)n)/(2n+1)!| ≤ |x|2N+2/(2N+2)!


I really don't know where to start. should I change the sums to series first then work my way through? Please help!
 
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Those are alternating series. The error bound is just the next element of the series.
 
ohhhhh wow now i see. thanks so much!
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

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