Sunday

August 31, 2014

August 31, 2014

Posted by **Jade** on Wednesday, June 18, 2014 at 8:59pm.

2. Given the terms a10 = 3 / 512 and

a15 = 3 / 16384 of a geometric sequence, find the exact value of the first term of the sequence.

- Math -
**Reiny**, Wednesday, June 18, 2014 at 10:55pm1

term(n) = ar^(n-1)

term(10) = 16(-1/2)^9

= 16(-1/512)

= - 1/32

2.

ar^9 = 3/512

ar^14 = 3/16384

divide the 2nd by the first

r^5 = 1/32

r = 1/2

back into the first

a(1/2)^9 = 3/512

a(1/512) = 3/512

a = 3(512)/512 = 3

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