Posted by KIRA on Wednesday, February 20, 2008 at 8:09pm.
how can you determine whether a design has rotational symmetry? if a design has a rotational symmetry, how many can you find the angle of roation??
- math - Damon, Wednesday, February 20, 2008 at 8:31pm
rotation matrix for rotation angle T
|cos T |-sin T|
|sin T | cos T|
That matrix, call it M
then M (column x|y) gives new x|y
for example if T = 90 degrees
| 0 |-1 | [x]
| 1 | 0 | [y]
0 x - y = -y for new x value
1 x + 0 y = x for new y value
SO you can reverse that
new x = old x cos T - old y sin T
new y = old x sin T + old y cos T
If you have a bunch of old x and y values and their corresponding new values, you can solve for sin T and Cos T and therefore for T, the rotation angle.
Answer this Question
More Related Questions
- Math - Determine whether a regular decagon has reflection symmetry and/or ...
- Math - Describe all symmetries of an oval. A) 4 lines of reflectional symmetry B...
- math - Multiple choice question. Describe all symmetries of a square. A) 2 lines...
- Math - What characteristics help you determine whether a polyhedron is regular ...
- Geometry - Can someone please kind enough to explain this questions for me. ...
- Geometry - How do the axes of rotational symmetry of an octahedron compare to ...
- Geometry - 1.1.Determine whether the regular pentagon has reflection symmetry, ...
- math - how can u determine whether a design has a reflectional symmetry??
- Math - Name a flat surface in nature that has reflection symmetry and one that ...
- Math questions - What are some examples of regular polyhedra? What are some ...