12.6. Composition of Transformations http://www.ck12.org
D( 3 ,− 1 )→D′(− 3 , 1 )
E( 8 ,− 3 )→E′(− 8 , 3 )
F( 6 , 4 )→F′(− 6 ,− 4 )
If you recall the rules of rotations from the previous section, this is the same as a rotation of 180◦.
- First, reflect the square overy=x. The answer is the red square in the graph below. Second, reflect the red square
over thex−axis. The answer is the green square below. - Let’s use the theorem above. First, we need to figure out what the angle of intersection is fory=xand thex−axis.
y=xis halfway between the two axes, which are perpendicular, so is 45◦from thex−axis. Therefore, the angle