Respuesta :

irspow
-16=ar^4 divided by 1024=ar is:

-1/64=r^3

r=-1/4

1024=a(-1/4), a=-4096 so

a(n)=-4096(-0.25^n)

a(7)=-4096(-0.25^7)=0.25

Answer:

the 7th term of the geometric sequence is 1/4  or 0.25

Step-by-step explanation:

Given geometric sequence terms

a1 = 1,024 and a4 = −16

nth term of geometric sequence is

[tex]a_n= a_1(r)^{n-1}[/tex]

a1 = 1,024 and a4 = −16

Plug in 4 for n and solve for 'r'

[tex]a_4= a_1(r)^{4-1}[/tex]

[tex]-16= 1024(r)^{3}[/tex]

Divide both sides by 1024

[tex]\frac{-1}{64} = r^3[/tex]

Now take cube root on both sides

[tex]\frac{-1}{4} = r[/tex]

To find 7th term we plug in n=7 , r= -1/4 , a1 = 1024

[tex]a_n= a_1(r)^{n-1}[/tex]

[tex]a_7= 1024(-1/4)^{7-1}[/tex]

[tex]a_7= 1024(-1/4)^{6}[/tex]

a_7 = 0.25