# Yahoo Web Search

1. ### rotation of 90 degrees ?

Rotation by counterclockwise is the same thing as pretending the positive y-axis... you see how that gets you the result? If not, try to prove that rotation is a linear transformation (there is a nice way to do this geometrically) and...

2 Answers · Science & Mathematics · 21/04/2009

2. ### Rotation about coordinates problem?

... wish to find its new coordinates after rotation about (-2,0). To deal with this we imagine that the origin... is a standard result very similar to the rotation of axes which you can easily confirm by simple trigonometry...

1 Answers · Science & Mathematics · 02/03/2011

3. ### a rotation matrix reprsentation?

Rotation by half the angle. If R(theta/2) is the rotation matrix for angle theta/2, R(theta/2)*R(theta/2) is two rotations by theta/2, equivalent to a single rotation by theta which is R(theta).. .

2 Answers · Science & Mathematics · 01/03/2013

4. ### Lesson 9.3 Rotation ?

For rotation by 270°, (x, y) becomes (y, -x). Considering the x- and y-...

4 Answers · Science & Mathematics · 27/07/2017

5. ### 3d rotations to form a mirror reflection?

Actually, it is not a rotation about the z-axis. It's a reflection in the y-z plane...that person IS in a position that is a 180 degree rotation about the z-axis. So when we look in a mirror, where the...

2 Answers · Science & Mathematics · 22/09/2011

6. ### help with trig ( rotation of conics)?

...apply a translation to reduce it to central form. If a rotation θ anticlockwise is applied to a point (x,y) the.../9 = 1. This is equivalent to a further rotation of ±90. Choose +90 so the total rotation is...

1 Answers · Science & Mathematics · 24/05/2011

7. ### How to find the center of rotation ?

...you are not given the location of the axis of rotation , I think that from a pure mathematical perspective it ...on the wheel to change the instantaenous center of rotation from the wheel axle to the point of contact between the rim of...

2 Answers · Science & Mathematics · 19/03/2012

8. ### What is the result of a rotation followed by a translation? What is the rotocenter of the resulting rotation ?

Notice that rotations always have exactly one fixed point, the center of rotation . So we just need...an attempt. Consider the translation vector and the center of the given rotation . They define a triangle with two vertices at the endpoints...

1 Answers · Science & Mathematics · 19/12/2010

9. ### Isometry and rotations ?

... -4/1. Suppose this is tan(phi). Then theta for the rotation must be -phi so that A will map to the x-axis after the rotation . Thus...

2 Answers · Science & Mathematics · 04/04/2011

10. ### Rotation of Axes?

... + Bxy + Cy² + Dx + Ey + F = 0 © angle of rotation : α cot (2α) = (A-C)/B the transformation of variables...

1 Answers · Science & Mathematics · 19/08/2007