Express the sum using sigma notation: 1 plus 3 over 4 plus 5 over 9 plus 7 over 16 plus 9 over 25

Question

Express the sum using sigma notation:

 (2 points)

A
B
C
D

Answer 1

When looking at this series, one can see three things:

1. It is finite and runs from 1 to 5, inclusive.
2. The numerators are made-up of odd integers.
3. The denominators are the squares of the index.

Therefore, one can write the cases as follows:

1. ∑ (well, hard to do with what is provided here on Wyzant)
2. Odd numbers for each index "k" may be written as 2k-1
3. Squares of each index "k" may be written as k²

Obtaining choice "C"