**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

... 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

**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

For

**rotation**by 270°, (x, y) becomes (y, -x). Considering the x- and y-...4 Answers · Science & Mathematics · 27/07/2017

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

...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

...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

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

... -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

... + 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