ALGEBRA II INTRODUCTION TO SERIES

SERIES : The sum of part (partial) or all of the terms of a sequence. The sequence 3, 8, 13, 18 can be written as the series ∑ is the Greek letter sigma which means summation. 2 k = is called sigma notation.

1) What does SOLUTION : ) What does SOLUTION : t 1 + t 2 + t 3 + t 4 + … + t n

3) Evaluate. SOLUTION : = (2 3 1 ) + (2 3 2 ) + (2 3 3 ) + (2 3 4 ) = = 240

4) Evaluate. SOLUTION : = (-1) 0 [3(0) – 2] + (-1) 1 [3(1) – 2] + (-1) 2 [3(2) – 2] + (-1) 3 [3(3) – 2] + (-1) 4 [3(4) – 2] + (-1) 5 [3(5) – 2] = = -9

Write using sigma notation. 5) S 30 = … SOLUTION : Hey, those numbers are all cubes.

6) S 50 = … SOLUTION : Hmmm, the numbers are all multiple of 3, so let’s factor out a 3. 3( …) Holy cow, look at the numbers in the (), they are all powers of 2. OR

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