Radian
1 Radian or 1 rad is an arc of radius length on circumference of a circle. Where radius is radius of the circle.
- Circumference of circle = 2Pi rad = 360 degree
90 degree = 1.57 rad
Rotation matrix
- Used to perform a rotation in Euclidean space.
For example, using the convention below, the matrix
R = [ cos θ | − sin θ ]
[ sin θ | cos θ ]rotates points in the xy plane counterclockwise through an angle θ about the origin of a two-dimensional Cartesian coordinate system.
Euclidean Space
- Represents physical space.
- Euclidean 3-spaces = x,y,z 3D plane
Cartesian Coordinate
- Represents each point in a plane by a pair of real numbers. Or 3 coordinates in a 3d space.
- n Cartesian coordinates specify the point in an n-dimensional Euclidean space for any dimension n.