Rotation Transformations

Front

What is a rotation transformation?

Back

A rotation transformation is a movement of a figure around a fixed point, called the center of rotation, by a certain angle in a specified direction.

Front

What is the rule for rotating a point (x, y) 90 degrees counterclockwise around the origin?

Back

The rule is (x, y) → (-y, x).

Front

What is the rule for rotating a point (x, y) 180 degrees around the origin?

Back

The rule is (x, y) → (-x, -y).

Front

What is the rule for rotating a point (x, y) 270 degrees counterclockwise around the origin?

Back

The rule is (x, y) → (y, -x).

Front

How many quadrants are there in a coordinate plane?

Back

There are 4 quadrants in a coordinate plane.

Front

What direction does a clock move?

Back

A clock moves in a clockwise direction.

Front

What is the opposite direction of clockwise?

Back

The opposite direction of clockwise is counterclockwise.

Front

If a point (3, 4) is rotated 90 degrees counterclockwise around the origin, what is the new position?

Back

The new position is (-4, 3).

Front

If a point (2, -3) is rotated 180 degrees around the origin, what is the new position?

Back

The new position is (-2, 3).

Front

What happens to the coordinates of a point when it is reflected over the x-axis?

Back

The y-coordinate changes sign: (x, y) → (x, -y).