I know what is a cartesian product of sets, for example, $M= \{1,2\} , N = \{a,b\} $
$M \times N = {(1,a), (1,b), (2,a) , (2,b)}$
but what is the Cartesian product of two intervals? say,
$[-5,1] \times [-2,3]$
I know what is a cartesian product of sets, for example, $M= \{1,2\} , N = \{a,b\} $
$M \times N = {(1,a), (1,b), (2,a) , (2,b)}$
but what is the Cartesian product of two intervals? say,
$[-5,1] \times [-2,3]$
By definition it is the set of couple:
$$
\{(x,y)|x\in[-5,1]\land y\in[-2,3] \}
$$
so it the rectangle $EFGH$ in the figure.
