Snapshot #3 Review

Given the translation rule (x,y) → (x + 7, y – 11), write the translation rule that maps A'B'C' onto ABC.

• (x,y) → (x – 7, y + 11)

• (x,y) → (y + 7, x - 11)

• (x,y) → (x + 7, y + 11)

• (x,y) → (x – 7, y – 11)

Mathematical Equivalence

ON

Study the given figure.  If it has reflectional symmetry, describe the line(s) of symmetry. Hint: Reflectional symmetry is the same as line symmetry in your notes.

• ​No, it has no reflectional symmetry.

• Yes, it has horizontal line symmetry and vertical line​ symmetry, but no other reflectional symmetries.

• Yes, it has reflectional symmetry about any line passing through the center.

• Yes, it has vertical line​ symmetry, but no other reflectional symmetries.

Triangle ABC has vertices A(−5, 6), B(−3, 2), and C(−1, 2). If △ABC is reflected across the x-axis and translated using the following rule

(x, y)→(x+2, –2y). What are the vertices of the image of △ABC ?

• A'(−3, -6), B'(3, -2), C'(5, -2)

• A'(−3, -12), B'(-1, -4), C'(1, -4)

• A'(−3, 12), B'(3, -4), C'(5, 4)

• A'(−3, -12), B'(-3, 4), C'(5, -4)

What is the horizontal stretch rule that maps P(–5, 3)

to P′(5, -9)?

• (x, y)→(x, 3y)

• (x, y)→(–x, –y)

• (x, y)→(-x, -3y)

• (x, y)→(–3x, y)

Find the value of each variable. Express answers in simplest radical form.