what will be the smallest disc where eigenvalues are located-untitled.jpg
Pick out the smallest disc (and explain why ) in the complex plane containing all the eigenvalues
of A from amongst the following:
a. |z - 1|<= 7;
b. |z - 1|<= 6;
c. |z - 1|<=4.

P.S: i know gershgorin theorem.but how to find the smallest circle? confused.

Thanks in advance.Regards