
Bradford T. answered 03/16/21
Retired Engineer / Upper level math instructor
an = (-1)n+13n/2n+1 = (-1)n+1bn
Using the Alternating Series Test, bn is not decreasing
lim bn = lim 3n/2n+1 = (1/2) lim (3/2)n = ∞ ≠ 0
n→∞ n→∞ n→∞
The answer is D) The value of the series is not a finite number