Talk:Sum of Infinite Series of Product of Power and Sine
Jump to navigation
Jump to search
Removed the note:
It is noted that when $x$ is a multiple of $2 \pi$ then:
- $1 - 2 r \cos x + r^2 = 1 - 2 + 1 = 0$
leaving the right hand side undefined.
This is not accurate since $r \in \R$ such that $\size r < 1$.
Therefore:
- $- 2 r \cos x \gt - 2$
Therefore:
- $1 - 2 r \cos x + 1 \gt 0$. --Robkahn131 (talk) 01:51, 18 March 2021 (UTC)