I dont understand what you do when you find when the expansion of a function is valid. I have gathered from examples that if it is:
valid for when 2x<1 so when x<1/2
but dont quite get it, just seeing the pattern from examples. The question I have is stating whether the series expansion i got (2-2x+10x^2) is valid for x=1/2. I thought you got when it is valid from the orginal function you expand?!?!
binomial expansion help! Watch
- Thread Starter
- 09-02-2010 18:03
- 09-02-2010 18:44
It's all about whether the series you get converges.
Sometimes you can expand the same expression in different ways, and you might choose the one that does the job.
I don't get what specific series you are working on.
(1-2x)^-1 starts to expand to 1 + (-1)(-2x) + (-1)(-2)(-2x)^2 / 2! + ....