Series and Sigma Notation 6

ALTERNATING SIGNS:

These will come up a lot!

We know how to generate the evens

But, what if the signs alternate?

Using one of these will fix it:

Which of these you use depends on where you start your index and if the thing starts with a positive or a negative. I know you don't believe me, so check it out:

the summation of 2k ( - 1 )^k as k goes goes from 1 to infinity = -2 + 4 - 6 + 8 - ... (the ( -1 ) is multiplied in)

the summation of 2k ( -1 )^( k + 1 ) as k goes from 1 to infinity = 2 - 4 + 6 - 8 + ...

the summation of 2k ( -1 )^( k - 1 ) as k goes from 1 to infinity = ___

TRY IT:

Write the sigma notation for

1 2 3 4 5 6

of 6

Series and Sigma Notation

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