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

2 Answers
Jul 26, 2017

#1, 1/2,1/4,1/8,1/16#

Explanation:

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

When #n=1#, #ar^(n-1)# becomes #1times(1/2)^(1-1)=1times1# (anything to the power of zero is one).

When #n=2#, #ar^(n-1)# becomes #1times(1/2)^(2-1)=1times1/2# and so on.

Jul 26, 2017

#1,1/2,1/4,1/8,1/16#

Explanation:

#"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#