\[ \displaystyle S_n = \sum _{ r=1 }^{ n }{ \big[(r-10)(r-20) \big] } \]
###### Image Credit: Wikimedia Cubix by Dohduhdah

Given the above function of \(S_n \), what does the summation below equal to?

\[\displaystyle \sum _{ r=1 }^{ 50 } \big|(r-10)(r-20)\big| \]

×

Problem Loading...

Note Loading...

Set Loading...