0 votes 0 votes Show that the only elements in $M_{n}\left ( \mathbb{R} \right )$ commuting with every idempotent matrix are the scalar matrices. ($A$ matrix $P$ in $M_{n}\left ( \mathbb{R} \right )$ is said to be idempotent if $P^{2}=P$.) TIFR tifrmaths2017 + – soujanyareddy13 asked Aug 30, 2020 • edited Sep 30, 2020 by soujanyareddy13 soujanyareddy13 145 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.