Tìm kiếm
Nam
$= (A^2-B^{2.2012})(A^{2(r-1)}+A^{2(r-2)}B^{2.2012}+...+A^2B^{2.2012(r-2)}+B^{2.2012(r-1)})$
$=(A-B^{2012}) (A+B^{2012})(A^{2(r-1)}+A^{2(r-2)}B^{2.2012}+...+A^2B^{2.2012(r-2)}+B^{2.2012(r-1)})$
$\Rightarrow \det(A+B^{2012})\det(A-B^{2012})\det(A^{2(r-1)}+A^{2(r-2)}B^{2.2012}+..+A^2B^{2.2012(r-2)}+B^{2.2012(r-1)})$
$=\det A^{2r}=(\det A)^{2r} \neq 0$
$\Rightarrow \det(A+B^{2012})\neq 0$
- phata1pvd, 1110004, ssupermeo và 2 người khác yêu thích
