Reflections in Coordinate Geometry

The video tutorial explains isometries, focusing on reflections. It covers reflections over the y-axis, x-axis, and the line y=x, detailing how coordinates change during these transformations. The tutorial emphasizes that reflections preserve congruence and explains the rules for transforming coordinates in each case.

What is an isometry?

• A transformation that only rotates a figure

• A transformation that alters the shape of a figure

• A transformation that preserves congruence

• A transformation that changes the size of a figure

Which of the following is not an isometry?

• Dilation

• Translation

• Rotation

• Reflection

What happens to a figure when it is reflected over the y-axis?

• The y-coordinates change

• The figure rotates 90 degrees

• Both x and y coordinates change

• The x-coordinates change

In a reflection over the y-axis, if point A is at (4, 5), where will A' be?

• (-4, 5)

• (4, -5)

• (-4, -5)

• (5, 4)

What is the rule for reflecting a point over the y-axis?

• (x, y) becomes (x, -y)

• (x, y) becomes (-x, y)

• (x, y) becomes (-x, -y)

• (x, y) becomes (y, x)

When reflecting over the x-axis, which coordinate changes?

• Only the y-coordinate

• Neither coordinate

• Only the x-coordinate

• Both x and y coordinates

If point B is at (3, 2) and is reflected over the x-axis, where will B' be?

• (2, 3)

• (-3, 2)

• (3, -2)

• (-3, -2)

What is the rule for reflecting a point over the x-axis?

• (x, y) becomes (y, x)

• (x, y) becomes (-x, -y)

• (x, y) becomes (x, -y)

• (x, y) becomes (-x, y)

What happens to the coordinates of a point when it is reflected over the line y = x?

• The coordinates are swapped

• The y-coordinate becomes negative

• The point remains unchanged

• The x-coordinate becomes negative

If point D is at (4, 7) and is reflected over the line y = x, where will D' be?

• (7, 4)

• (-4, 7)

• (4, -7)

• (-7, -4)