COMPUTER SCIENCE AND ENGINEERING
COMPUTER GRAPHICS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Lower left corner of an object
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Origin of the Co-ordinate system
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All points of the object
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None of the above
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Detailed explanation-1: -The rotation of a point ( , ) by 180 degrees is represented by the coordinate transformation ( , ) → ( − , − ) . The rotation of a point ( , ) by 270 degrees is represented by the coordinate transformation ( , ) → ( , − ) .
Detailed explanation-2: -Rotation about the Origin is a transformation that rotates or turns a figure (e.g., a triangle) about the origin point (x, y)→(0, 0). ( x, y ) → ( 0, 0 ) . Angle of Rotation: The number of degrees that a figure is turned or rotated about the origin.
Detailed explanation-3: -90° counterclockwise rotation: (x, y) becomes (-y, x) 180° clockwise and counterclockwise rotation: (x, y) becomes (-x, -y) 270° clockwise rotation: (x, y) becomes (-y, x) 270° counterclockwise rotation: (x, y) becomes (y, -x)
Detailed explanation-4: -Since matrix multiplication has no effect on the zero vector (the coordinates of the origin), rotation matrices describe rotations about the origin. Rotation matrices provide an algebraic description of such rotations, and are used extensively for computations in geometry, physics, and computer graphics.