Question

DateSequences and SeriesIntroduction to Geometric Series - Part 1Independent Practice1. Determine if the following scenarios are a geometric series, geometric sequence, orneither. Use SE for a geometric series, use SQ for a geometric sequence, and use N forneither.3, 6, 12, 24, 48, ...-4 + 1 + 6 + 11 + ...100,50, 25, 12.5,...162 + 108 + 72 + 48 + ...40.5 + 13.5 + 4.5 + 1.5 + ...3,8,13,18, 23,...2. A geometric series is defined by an = -2(-5)". Find the geometric series of the first fiveterms.

Answer 1

Part 1)

3,6,12,24,48 ... Is geometric ,with ratio= 6/3=2

-4,+1,+6,+11... is arithmetic , ratio 1--4= 5

100,50,25,12,5... Is geometric , decreasing ratio= 50/100= 1/2

162, 108, 72, 48... Is Neither

40.5, 13.5, 4.5, 1.5... is geometric, decreasing ratio= 1/3

3,8,13,18,23 ... Is arithmetic, increasing ratio = 5

Part 2)5

an = -2(-5)^n

First five terms are

a1= -2

a2= 10

a3 = -50

a4 = +250

a5 = -1250