If A = A={(x,y):y=1x,0≠xϵR} and B = {(x,y):y=−x,xϵR}, then write A∩B.
Let zϵA∩B
⇒z ϵA and z ϵB
⇒z ϵ{(x,y):y=1x,0≠x ϵR} and
z ϵ{(x,y):y=−x,x ϵ R}
⇒z ϵ{(x,y):−x=1x,0≠x ϵ R}
⇒z ϵ{(x,y):x2=−1,x ϵ R}
⇒z ϵ{ }
Therefore A∩B is an empty set.
If A={(x,y):y=ex,x belongs to R} and B={(x,y):y=e-x,x belongs to R}, then write A intersection B.