Assuming the series is

The series will converge if

We have

So the series will certainly converge if

, but we also need to check the endpoints of the interval.
If

, then the series is a scaled harmonic series, which we know diverges.
On the other hand, if

, by the alternating series test we can show that the series converges, since

and is strictly decreasing.
So, the interval of convergence for the series is

.
The answer is the third one
Answer:
If 40 wrong then I am sorry.
Step-by-step explanation:
x < −8/21
if you need help with explanations of the equations, "mathpapa" is something to look up. It's a algebra calculator that explains the step by step process
Angle 6, angle 4, angle 3, and angle 2 are all exterior angles.
Hope this helps!