Reflections Over Diagonal Lines

What is a reflection?

• When you turn an object around a point.

• When you flip or mirror an object across a line.

• When you slide an object from one place to another.

• When you resize an object.

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

What is the rule for a reflection across the y = x line?

• (x, y) becomes (x, -y)

• (x, y) becomes (-x, y)

• (x, y) becomes (-x, -y)

• (x, y) becomes (y, x)

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Graph the reflection with line of reflection y=x. Point C is currently located at (3,1). What are the new coordinates of C' ?

• (3, 1)

• (1, 3)

• (-3, -1)

• (-3, 1)

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

What are the new coordinates of A' after a reflection across the line y=x?

• (1,1)

• (1, 2)

• (2,1)

• (-1, 2)

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

What is the new location of image point C' when reflected over the line y=x ?

• (0, 2)

• (0, -2)

• (2, 0)

• (0, 0)

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

What is the new location of image point B' when reflected over the line y=x ?

• (-6, 2)

• (-8, 9)

• (9, -8)

• (2, -6)

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

What is the rule for a reflection across the y = --x line? Remember this is a negative diagonal line through the origin.

• (x, y) becomes (x, -y)

• (x, y) becomes (-x, y)

• (x, y) becomes (-y, -x)

• (x, y) becomes (y, x)

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Graph the reflection with line of reflection y= -x. Point C is currently located at (3,1). What are the new coordinates of C' ?

• (3, 1)

• (1, 3)

• (-3, -1)

• (-1, -3)

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

What is the new location of image point B' when reflected over the line y= -x ?

• (-6, 2)

• (-2, 6)

• (9, -8)

• (2, -6)

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

What is the equation of this line? (Notice, it is decreasing.)

• x = 0

• y = 0

• y = x

• y = -x