Question

WILL FAN AND MEDAL
What are the explicit equation and domain for a geometric sequence with a first term of 4 and a second term of -8?

Answer 1

an=4(-2)^n-1; all integers where n≥0
an=4(-2)^n-1; all integers where n≥1
an=4(-12)^n-1; all integer where n≥0
an=4(-12)^n-1; all integer where n≥1

Answer 2

ok... just a correct.... you answer choices are for a geometric sequence and your question mentions an arithmetic sequence..

Answer 3

Sorry fixed it

Answer 4

so to get from 4 to -8 by multiplying the common ratio is -2

and a term in a geometric sequence is found using

\[a_{n} = a_{1} \times r^{n - 1}\]

where \[a_{1} ~ 1st ~term~~~~~~and~~~ r = common ~ratio\]

the domain is

\[n \ge 1\]

so substitute what you know into the general equation to get the explicit form

Answer 5

Oh okay thank you :)