Friday

December 19, 2014

December 19, 2014

Posted by **KIRA** on Wednesday, February 20, 2008 at 8:09pm.

- math -
**Damon**, Wednesday, February 20, 2008 at 8:31pmrotation 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]

gives

0 x - y = -y for new x value

and

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**

**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 ...

math - how can u determine whether a design has a reflectional symmetry??

Math questions - What are some examples of regular polyhedra? What are some ...

geometry - What is a quadrilateral that has a line of symmetry but no rotational...

geometry - Which type(s) of symmetry does the uppercase letter H have? my answer...