Answer:
The first term is 28.
Step-by-step explanation:
Given: 8th term of Geometric sequence , [tex]a_8=-3584[/tex]
and 3rd term of Geometric Sequence, [tex]a_3=112[/tex]
We have to find First term of given geometric Sequence.
Let a be the first term of geometric sequence.
We know that,
[tex]a_n=ar^{n-1}[/tex]
So,
[tex]\frac{a_8}{a_3}=\frac{ar^{8-1}}{ar^{3-1}}=\frac{-3584}{112}[/tex]
[tex]\frac{r^{7}}{r^{2}}=-32[/tex]
[tex]r^5=-32[/tex]
[tex]r=-2[/tex]
So, [tex]a_3=112[/tex]
[tex]a\times(-2)^{2}=112[/tex]
[tex]a=\frac{112}{4}=28[/tex]
Therefore, The first term is 28.
