Step-by-step explanation:
Set of points (x,y) satisfying [y]=[x] is equal to
⋃i∈Z[i,i+1)×[i,i+1) .
OR
Say, k≤x<k+1 , for some integer k
Then [x]=k
And according to the question, [y]=k . Now we just need to find for which values of y , [y]=k
Clearly, for every y in the interval [k,k+1) , the relation holds.
Let K=[k,k+1)
So the ordered pair (x,y) lies in the region denoted by the set ∪ K×K , where K=[k,k+1) for every integer k
BOTH ARE CORRECT JUST DIFFERENT WAYS
