# Math Help - power series, determine radius of convergence.

1. ## power series, determine radius of convergence.

find a power series representation, and determine the radious of convergence.

function:

ln(5-x)

thankyou for any help.

2. Originally Posted by rcmango
find a power series representation, and determine the radious of convergence.

function:

ln(5-x)

thankyou for any help.
Note that,

1+y+y^2+... = 1/(1-y) for |y|<1

If y=x-4 with |x-4|<1 then,

1+(x-4)^2+(x-4)^2+... = 1/(5-x)

Integrate term by term to get the series for ln |5-x|

3. thanks for the help.