Here is an article on how calculators compute functions like logs and exponentials. Click Here

Here is a problem set on Complex Numbers, Indeterminate Forms, and Power Series

And a problem set on more power series calculations.

Here is the homework on Indeterminates and Probability

The following is about rates of convergence of power series and helps to explain how Feynman could do certain calculations in his head.

Next, this file gives part of the proof of the error theorem for power series, which bounds how far you can be from the exact answer if you stop after finitely many terms.

Finally, this file explains the Ratio Comparison Test, which is different from the plain ratio test.