Question

Can someone help me please? I don't understand this stuff :c

Consider the infinite geometric series (I'll type it in the comments)... In this image, the lower limit of the summation notation is "n=1".

a. Write the first four terms of the series.
b. Does the series diverge or converge?
c. If the series has a sum, find the sum.

Answer 1

\[\sum_{n=1}^{\infty}-4(1/3)^{n-1}\]

Answer 2

i think we can use the geometric series test
"If |r| < 1 then the following geometric series converges to a / (1 - r).

If |r| >= 1 then the above geometric series diverges."

Answer 3

find the first time by plugging in n=1
c^0=1 so we're left with a =-4