Question

Write a formula for the general term (the nth term) of the geometric sequence. 1/2 ; -(1/10) ; 1/50 ; -(1/250), .....

A. an = (1/2)n - 1(3/5)
B. an = 1/2 - 1/5(n - 1)
C. an = 1/2(-1/5)n - 1
D. an = 1/5(-1/2)n - 1

Answer 1

Alright, I sort of understand.

Answer 2

1/25, right?

Answer 3

Good..

Can you do it for second one now??

Answer 4

It's also 1/25, is it not?

Answer 5

Oh no!

Answer 6

And to think, it was making sense. -laughs-

Answer 7

Ha ha ha...

Answer 8

See, simply find r by dividing second term with first term that is 1/2 with -1/10 ...

Answer 9

Divide -1/10 by 1/2..

Answer 10

Which is -1/5, so... Looking at my options.

Answer 11

Yes it is -1/5..

Answer 12

We must have to find another though, right?

Answer 13

\[\large a_n = a \cdot r^{n-1} \implies \frac{1}{2} \cdot (-\frac{1}{5})^{n-1}\]

Answer 14

What choice is this??

Answer 15

*which

Answer 16

C.

Answer 17

Good...

Answer 18

That was depressingly easy. Thank you!

Answer 19

For showing exponent or power, please use "^" this sign..

Answer 20

You are welcome dear...