Math

1. Find the 11th term of the geometric sequence 64, -32, 16, -8, … .

2. Find the 1st term of a geometric sequence with a 10th term -1024 and r = -2.

3. Find the sum of each infinite geometric series, if possible.
a. 10 + 2 + 2/5 + .....
b. 1.2 – 2.4 + 4.8 – 9.6 + .....
c. 3 – 1 + 1/3 – 1/9 + 1/27 + ...

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1. #1
clearly, r = -1/2
T11 = ar^10

#2
a(-2)^9 = -1024

#3
Just recall that S = a/(1-r)
then plug in the numbers

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2. 👎 1

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