13. In the above figure, points A, B, C, D and E are on the xy coordinate plane. If these points are mapped to the other end of a straight line with Y=x, find out how many points mapped in the past are the negative products of x coordinates and y coordinates.

Answer:

A, B, C and E are in the fourth quadrant, and their coordinates all conform to the fact that X is negative and Y is positive.

D on the y-axis, the coordinates correspond to that x is 0 and y is a positive number.

After mapping, the coordinates of the four-point images of A, B, C and E conform to that X is positive and Y is negative, so the product of X and Y coordinates is (positive * negative) = negative;

The coordinate of the image of point D is 0, Y is negative, and the product of its xy coordinates is (0* negative) = 0;

Therefore, the product of xy coordinates of four points A, B, C and E in the past storage of the map is negative.

Choose e.