- #1

stukbv

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- 0

## Homework Statement

Sum 1/n(n+1) * (sin(x))^n .

Show this converges for all x in the reals.

Find with proof an interval on which it determines a differentiable function of x together with an expression of its derivative in terms of standard functions.

## Homework Equations

## The Attempt at a Solution

I have showen convergence via a comparison to sum 1/n(n+1) so this is okay,

I think now we let x=sinx and write it like ;

Sum 1/n(n+1) * x^n .

Differentiating this gives you 1/(n+1) * x^n-1 now basically am stuck again :(

Thankyou!