‌BCB−1=A ‌⇒(BCB−1)(BCB−1)=A⋅A ‌⇒BCI‌CB‌‌−1=A2 ‌⇒BC2B−1=A2 ‌⇒B−1(BC2B−1)B=B−1(A⋅A)B From equation (1) ‌C2=A−1⋅A⋅B ‌C2=B Also AB−1=A−1 ‌⇒AB−1⋅A=A−1A=I ‌⇒A−1(AB−1A)=A−1I ‌B−1A=A−1 Now characteristics equation of C2 is ‌|C2−λI|=0 ‌|B−λI|=0 ‌⇒|