> What about the 2 power series problems in the pictures ?
A: you can view the step by step solutions to find both the interval and radius of convergence of any power series under F3 1 within the sequence and series module of calculus made easy.
When entering both power series you will see that first the interval of convergence IOC is computed using the ratio test on the given nth terms , secondly the endpoints are evaluated separately and lastly the radius R of convergence is computed from the IOC.
Everything in step by step fashion yielding R=1 and IOC -1 to 1 exclusive endpoints.