Question

MEDAL please help
What is a rule for the nth term of the geometric sequence with a4=-18 and common ration r = 2?
A) an=-2.25(2)n-1
B) an=2.25(2)n-1
C) an=-2(2.25)n-1
D) an=2(2.25)n-1

Answer 1

so the formula you have to use is \[a _{n}=a _{1}r ^{n-1}\]