Answer :
Here looking at x in (x,y) pairs
[tex]\\ \sf\longmapsto 8\neq4\neq6\neq 7\neq 2[/tex]
- Every value has a unique image
- Hence its a function
[tex]\\ \sf\longmapsto D_f=\{8,4,6,7,2\}[/tex]
[tex]\\ \sf\longmapsto R_f=\{-2,-6,-8,5,4\}[/tex]
Here looking at x in (x,y) pairs
[tex]\\ \sf\longmapsto 8\neq4\neq6\neq 7\neq 2[/tex]
[tex]\\ \sf\longmapsto D_f=\{8,4,6,7,2\}[/tex]
[tex]\\ \sf\longmapsto R_f=\{-2,-6,-8,5,4\}[/tex]