How do you write the first five terms of the geometric sequence a_1=1, r=1/2a1=1,r=12?

2 Answers
Jul 26, 2017

1, 1/2,1/4,1/8,1/161,12,14,18,116

Explanation:

Geometric sequences are defined by the formula ar^(n-1)arn1 where aa is the first term and rr is the common ratio (i.e. the second term divided by the first term or third divided by second).

When n=1n=1, ar^(n-1)arn1 becomes 1times(1/2)^(1-1)=1times11×(12)11=1×1 (anything to the power of zero is one).

When n=2n=2, ar^(n-1)arn1 becomes 1times(1/2)^(2-1)=1times1/21×(12)21=1×12 and so on.

Jul 26, 2017

1,1/2,1/4,1/8,1/161,12,14,18,116

Explanation:

"the standard terms of a geometric sequence are"the standard terms of a geometric sequence are

a,ar,ar^2,ar^3,........ ,ar^(n-1)

"where a is the first term and r the common ratio"

"to obtain a term in the sequence multiply the previous"
"term by r"

"here "a=a_1=1" and "r=1/2

a_1=1

a_2=1xx1/2=1/2

a_3=1/2xx1/2=1/4

a_4=1/4xx1/2=1/8

a_5=1/8xx1/2=1/16