Answer:
C
Step-by-step explanation:
No doubt thats the correct answer guys, thank me later
Answer: 2.15, 2.2, 2.2012, 2.501
Answer: second option.
Step-by-step explanation:
You must apply 
Then, given the right triangle and the angle D, the opposite side and the hypotenuse of the triangle are the following:

Therefore, when you substitute values, you have:

Reduce the fraction, then you obtain:

I'm guessing the series is supposed to be

By the ratio test, the series converges if the following limit is less than 1.

The first

terms in the numerator's denominator cancel with the denominator's denominator:


also cancels out and the remaining factor of

can be pulled out of the limit (as it doesn't depend on

).

which means the series converges everywhere (independently of

), and so the radius of convergence is infinite.