Question

Find the sum of the geometric series

Answer 1

so, a1... a10, you have 10 terms

Answer 2

n = 10

Answer 3

since you knw a1, and r, you can use the geometric series sum formula directly ?

Answer 4

\(\large S_n = a_1(\frac{1-r^n}{1-r})\)

Answer 5

just plug and chug

Answer 6

i got 1/-1

Answer 7

how ?

Answer 8

im gona do it again

Answer 9

Ok :)

\(\large S_n = a_1(\frac{1-r^n}{1-r}) \)

\(\large S_n = -1(\frac{1-(-2)^{10}}{1--2}) \)

\(\large S_n = -1(\frac{1- 2^{10}}{1+2}) \)

= ?

Answer 10

341?

Answer 11

Yes !

Answer 12

gw! :)