Here's the question you clicked on:
hugsandkisses
When point B (5, -1) is rotated 180º about the origin, its coordinate becomes (-5, 1). True False
True http://www.wolframalpha.com/input/?i=plot+%285%2C-1%29+and+%28-5%2C1%29&a=*C.plot-_*PlotsWord-
Draw (5,-1) and then draw a circle that passes through (5,-1) with (0,0) as the origin. Using your picture, move halfway around the circle, 180 degrees, and we arrive at (-5, 1). TRUE!
thank you for explaining that!
at (x,y) at 180 degree =(-x,-y)
180 degree is rotation is just reflection about the origin
Think about odd functions ..