BC ONLY- (D) The series therefore converges if which is less than 1 if
which is less than 1 if −2 > x. Now for the endpoints:
x = 2 yields 1 + 1 + 1 + 1 + ..., which diverges;
x = −2 yields −1 + 1 − 1 + 1 − ..., which diverges.
The answer is |x| > 2.