Toronto Math Forum
MAT3342020S => MAT334Lectures & Home Assignments => Chapter 2 => Topic started by: serena li on March 01, 2020, 10:18:13 PM

For the question asking to find the powerseries expansion about the given point for the function and find the largest disc where the series are valid, I am confused about how to find the valid largest disc. Thank you so much.

Either investigate the power series or to use theorem that if $f$ is analytic in some disc $D(z_0,r)$, then the expansion at its center $z_0$ converges in this disc.