Translations part 1.

Transformations Part 1.

Reflections and Translations.

Notation

• Pre-image: the image before it is transformed. (Written A, B, C)

• Image: the image after it is transformed. (Written A', B', C') - pronounced "a-prime."

Reflections

• "Flipping" or mirroring an image on the other side of a mirror line.

• Whatever happens on one side of the mirror line, happens on the other side of the mirror line.

• ex: reflecting something over the x or y axis.

Multiple Choice

What is a reflection?

• When you turn an object around a point.
• When you slide an object form one place to another.
• When you flip or mirror an object across a line.
• When you resize an object.

Multiple Choice

Reflections over the x-axis change the ____-__________. 

• y-coordinate
• x-coordinate

Multiple Choice

Reflecting over the y-axis changes the ____-_____________. 

• x-axis
• x-coordinate
• y-coordinate
• y-axis

Multiple Choice

What is the Algebraic Notation for this Reflection?

• (x, y) → (y, x)
• (x, y) → (-x, y)
• (x, y) → (-y, -x)
• (x, y) → (x, -y)

Multiple Choice

What is the Algebraic Notation for this Reflection?

• (x, y) → (y, x)
• (x, y) → (-x, y)
• (x, y) → (-y, -x)
• (x, y) → (x, -y)

Multiple Choice

Find K' if the figure is reflected across the x-axis

• (4, 1))
• (-1, -4)
• (1, -4)
• (1, 4)

Translations

• "Sliding" a point or image by the same distance in a given direction.

• Sliding the x-coordinate: the point/image goes left or right.

• Sliding the y-coordinate: the point/image goes up or down.

• ex: (x+3, y-4)

Multiple Choice

What does a translation do to an image?

• Turns it 90* clockwise
• Mirrors it
• Shrinks it
• Slides it

Multiple Choice

What transformation is happening?
(x, y) ----> (x + 2, y - 3) 

• slide up 2, left 3
• slide right 2, up 3
• slide right 2, down 3
• slide left 3, right 2

Multiple Choice

What rule describes the translation?

• (x - 6, y + 2)
• (x - 2, y + 6)
• (x + 2, y - 6)
• (x + 6, y - 2)

Multiple Choice

Determine how to translate triangle A'B'C' to triangle ABC.

• (x+2, y-5)
• (x+2, y-9)
• (x-2, y-9)