hi
may i know what it means by R ^x where R= real numbers? and what does GL (subscript 2) (R) means?
thanks
For any field (or even commutative ring) $\displaystyle R\,,\,\,R^{*}:=R\setminus \{0\}\,\,\,(or\,\,\,R^{*}=$ the set of all units in the ring R) , and $\displaystyle GL_2(R)=$ the set of all invertible 2 x 2 matrices with elements in R (or the set of all R-automorphism of the R-module R x R)
Tonio