Quote:
Originally posted by Flatbutt1
I don't follow how you go to the Sum from 0 to infinity of X raised to the power of n is equal to 1/1-x.
I see that x =.9 and you bring it over as a constant
but why is that all dependant upon X being less than 1?
|
The second line is simply what a geometric series from 0->infinity is equal to, w/ |x|<1. |x|<1 is important b/c then the series converges [b/c as n goes to infinity, x goes to zero], if |x|>= 1 then the series diverges to infinity. In our case x does not = .9, x=1/10; .9 is a constant we can put outside the sum.