Part 1
the sixth term of a sequence is 128 and the common ratio is 2. use the explicit formula for a geometric sequence to find
the first term.
part 2
use the information from part 1 to write an explicit formula for the nth term of a geometric sequence. find the 21st term
of the sequence.
complete your work in the space provided or upload a file that can display math symbols if your work requires it. include
all of part 1 and part 2 in your answer.

see explanation

Step-by-step explanation:

Part 1

The n th term of a geometric sequence is

= a

where a is the first term and r the common ratio

Given = 128, then

a = 128, that is

32a = 128 ( divide both sides by 32 )

a = 4 ← first term

Part 2

= 4 = 4 × 1048576 = 4194304

80π/3 or about 83.775

step-by-step explanation:

since a cone is 1/3 of a cylinder, we need to find the base's area. since area = πr^2, we get 16π. then, multiplying this by 5, we get 80π. dividing by 3, since the cone's volume is 1/3 of that of a cylinder's, we get 80π/3.

hope this !

a is the right answer