Can we leave out the first few terms in a Taylor series before doing the ratio test? http://s12.postimage.org/gljh4ean0/what.jpg
we can leave out the first two terms? how come we can do that? is it because the series goes to infinity? can we do that for all taylor series even if we don't need to do it?

If you want to test convergence of any series, only the "tail" matters, and you can leave out as many terms as you want (as long as it is a finite number of terms, of course).
