Which of the following points is symmetric with y=x at (4,5)? Options.
A) (-2,-1) B) (-2,1) C) (2,1) D) (-1,-2) E) (5,4)
We can think of line y = x as a mirror. Any point (x,y) becomes (y,x) when it isreflectedover the mirror. Reverse the coordinate and keep the same sign. These two points will be symmetric to the line y = x.   (4,5) would become (5,4).   Answer ((5,4)).
<result>E</result>
Which of the following points is symmetric with y=x at (4,5)?