Enter your answer and show all the steps that you use to solve this problem in the space provided. Consider the infinite geometric series
∑∞n=1−4(1/3)^n−1
. 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.