Sect. 4-7 continued Transformations using matrices

Def: Geometric figures, called polygons, are made from straight lines and can be specified by the vertex points

The coordinates of the vertices can be places in a matrix, where the first row lists the x-coordinates and the second row the y-coordinates

1.) trapezoid PQRS is given by P(3, 5), Q(6, -5) R(-6, -5) and S(-3, 5). List the vertices in a matrix 2.) Let enter matrix [A] and matrix [B] into your calculator

2.) continued a) find [B][A] b) plot [A] and [B][A] c) what is the transformation?

For counterclockwise rotation 90° multiply by For 180° rotation clockwise, multiply by For counterclockwise rotation 270°, multiply by Rotational Transformations

Multiply the matrix by a matrix of the form To reduce a matrix 50%, multiply by To enlarge by 130%, multiply by To Enlarge or Reduce an object

3.) if a)Enlarge by 150% b)Reduce by 25%

Pre-Image Rotated 45 o Rotated 90 o and Doubled Points Matrix Image Transformations x = Computer Animation

Homework Practice and Apply worksheet 4-7