Your Practice Set – Applications and Interpretation for IBDP Mathematics SE Production Limited 78 � Two-dimensional transformation matrices : 1 . 1 0 0 1 � � � � � � � : Reflection about the x -axis 2 . 1 0 0 1 � � � � � � � : Reflection about the y -axis 3 . cos 2 sin 2 sin 2 cos 2 � � � � � � � � � � � : Reflection about the line y mx � , where tan m � � 4 . 1 0 0 k � � � � � � : Vertical stretch with scale factor k 5 . 0 0 1 k � � � � � � : Horizontal stretch with scale factor k 6 . 0 0 k k � � � � � � : Enlargement about the origin with scale factor k 7 . cos sin sin cos � � � � � � � � � � � : Rotation with positive angle � anticlockwise about the origin 8 . cos sin sin cos � � � � � � � � � � � : Rotation with positive angle � clockwise about the origin 9 . Area of the image det ( ) T � � Area of the object , where T is the transformation matrix Solutions of Chapter 7 SUMMARY POINTs