Learn a bit about the symmetry of a straight line in Flash (53) every day

Find the right of a (3, 1) on the linear x + Y-1 = 0

Best Answer

If the coordinate of the symmetric point is B (X, Y), the midpoint coordinate of AB is (3 + x)/2, (1 + Y)/2), and it is in a straight line.

(3 + x)/2 + (1 + Y)/2-1 = 0

(Y-1)/(X-3) = 1... (the slope of AB is 1)

Solution: x = 0, y =-2

 

Flash applications:

 

This is a problem on the Internet. It seems that it is not difficult at all.

Suppose we have a vertex A (x1, Y1), a straight line AX + by + c = 0 (or Y = kx + B ), the symmetric point B (X2, Y2) that requires this point. We know that the link between the two points is the line AB of the vertical line. According to the known conditions, ax + BYD + c = 0 slope k, then the slope of the line AB is the reciprocal to the negative,-1/K ,.

 

T =-1/K;, t = (y2-y1)/(x2-x1 );

The midpoint of AB is C (X1 + x2)/2, (Y1 + y2)/2 );

Place the intersection point into the straight line AX + by + c = 0 (y = kx + B ),

There are already two equations, and now the coordinates of point B are X2, y2.

The application here is very useful.

 

Suppose we have changed the coordinates of a to the coordinates of the mouse (xmouse, ymouse), and then we can change some results.