Question Number 74617 by Raxreedoroid last updated on 27/Nov/19
![Expand 1+Σ_(k=1) ^(n−1) [∣((2(√3))/3)sin(120x)∣+2]](https://www.tinkutara.com/question/Q74617.png)
$$\mathrm{Expand} \\ $$$$\mathrm{1}+\underset{{k}=\mathrm{1}} {\overset{{n}−\mathrm{1}} {\sum}}\left[\mid\frac{\mathrm{2}\sqrt{\mathrm{3}}}{\mathrm{3}}{sin}\left(\mathrm{120}{x}\right)\mid+\mathrm{2}\right] \\ $$