Question

F(Z)=Z*Z-Z-2分之一 如何展成Z的幂级数,并求出收敛半径.

Answer 1

F(z)=1/(z^2-z-2)=(1/3)(1/(z-2)-1/(z+1))

1/(z-2)=(-1/2)/(1-z/2)= (-1/2)(1+z/2+z^2/4+z^3/8+.|z|