Ch. 9 Flashcard Review

Front

Where would A' be if you translated A 3 units to the right and 4 units down?

Back

A' is at (-1, 0). To find this, add 3 to the x-coordinate and subtract 4 from the y-coordinate of point A.

Front

Dilate Point B by a scale factor of 1/2.

Back

The new coordinates of Point B after dilation by a scale factor of 1/2 are (-1.5, 1). This means you multiply each coordinate by 1/2.

Front

What is the image of S (2, -5) after a rotation of 90° clockwise about the origin?

Back

The image S' after a 90° clockwise rotation is (-5, -2). This involves switching the coordinates and changing the sign of the new x-coordinate.

Front

What is the rule for the following reflection across y = -1?

Back

To reflect a point across y = -1, subtract the y-coordinate of the point from -1 and then double that result, keeping the x-coordinate the same.

Front

Reflect the point (-2, -2) over the x-axis.

Back

The reflected point is (-2, 2). Reflecting over the x-axis changes the sign of the y-coordinate.

Front

What is the effect of translating a point 5 units left and 2 units up?

Back

The new coordinates will be (x - 5, y + 2). This means you subtract 5 from the x-coordinate and add 2 to the y-coordinate.

Front

How do you perform a dilation on a point?

Back

To perform a dilation, multiply each coordinate of the point by the scale factor.

Front

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

Back

When reflected over the y-axis, the x-coordinate changes sign, while the y-coordinate remains the same.

Front

What is the image of point (3, 4) after a 180° rotation about the origin?

Back

The image after a 180° rotation is (-3, -4). This involves changing the signs of both coordinates.

Front

What is the formula for reflecting a point (x, y) over the line y = k?

Back

The new coordinates after reflection over y = k are (x, 2k - y).