MathCastle
Groups and FieldsEasyA Gallery of Groups

A Gallery of Groups · Easy problem

Do A=(1101)A=\begin{pmatrix}1&1\\0&1\end{pmatrix} and B=(2001)B=\begin{pmatrix}2&0\\0&1\end{pmatrix}, both in GL(2,R)GL(2,\mathbb R), commute — that is, does AB=BAAB=BA?