## anonymous one year ago What are the explicit equation and domain for a geometric sequence with a first term of 4 and a second term of -8? (5 points) 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 integers where n ≥ 1 an = 4(-12)n - 1; all integers where n ≥ 0

1. anonymous

PLEASE SOME ONE HELP

2. misty1212

HI!!

3. anonymous

hi!

4. anonymous

do you mind helping me with this

5. anonymous

i believe that the answer is the third one but im not sure

6. misty1212

$a,ar,ar^2,ar^3...$ $4,4\times r=-8$

7. misty1212

if $4\times r=-8$ then $r=\frac{-8}{4}=-2$

8. anonymous

okay

9. misty1212

therefore $a_n=4\times (-2)^{n-1}$

10. anonymous

so is it a or b???

11. misty1212

it would be B

12. anonymous

okay thank you

13. misty1212

because $$n\geq 1$$ is what they want as the domain

14. misty1212

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