1. EXAMPLE 4
Write series using summation notation
Write the series using summation notation. 3 4 2 1 5 b. +
. . . a
SOLUTION
Notice that the first term is 25(1), the second is 25(2), the third is 25(3), and the last is 25(10). So, the terms of the series can be written as: a.
ai = 25i where i = 1, 2, 3, , 10
The lower limit of summation is 1 and the upper limit of summation is 10.

2. Write series using summation notation
EXAMPLE 4
Write series using summation notation
ANSWER
The summation notation for the series is 10
i = 1
25i.

3. Write series using summation notation
EXAMPLE 4
Write series using summation notation
Notice that for each term the denominator of the fraction is 1 more than the numerator. So, the terms of the series can be written as: b.
ai =
i + 1 i
where i = 1, 2, 3, 4, . . .
The lower limit of summation is 1 and the upper limit of summation is infinity.
ANSWER
The summation notation for the series is 8
i = 1
i + 1 i .

4. Write the series using summation notation.
GUIDED PRACTICE
for Example 4
Write the series using summation notation.
ANSWER 20
i = 1 5i 7. 10 5 17 + 9 4 1 2 16
ANSWER ∞
i = 1
i2 + 1 i2

5. Write the series using summation notation.
GUIDED PRACTICE
for Example 4
Write the series using summation notation.
ANSWER ∞
i = 1 6i 8
i = 1
4+ i
ANSWER