# summation with square

#### swah

How can I calculate $$\displaystyle ∑^2 \beta$$ from item 2?
The following equation from Kasa Method.
Thank you!

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#### Maschke

What are $\Sigma_\delta$ and all the rest of these symbols? Is there more context to this problem?

Oh I see they're defined in 1. But what is the context of this problem?