Question

for each pair funtion,find fog and gof , if they are exit
f = {(1,1),(0,-3)}
g = {(1,0),(-3,1),(2,1)}
fog= gof=
1 -3 2 1 0
0 1 1 1 -3
1 -3 0 1 1
fog={( , 0 ) , ( , )}
gof={( , 0 ) , ( , )}
need help please!