Question

Find the 15th term in the geometric sequence below. 20, 10, 5, 2.5, . . .

Answer 1

\(\Huge{a _{n}=a _{1}.r ^{(n-1)}}\)

Answer 2

How do i plug in the numbers?

Answer 3

you know the \(\Huge{a}\) , \(\Huge{n}\) , and \(\Huge{r}\) ??

Answer 4

sure...

Answer 5

show me them :D

Answer 6

yea i dont know aha

Answer 7

we search for \(\Huge{a _{15}}\)
\(\Huge{a _{1}=20}\)
\(\Huge{r=\frac{ 1}{ 2}}\)

Find!

Answer 8

\(\Huge{a _{15}=20.\frac{1}{2}^{(14)}}\)

Answer 9

oh i get ya

Answer 10

Yup lol