By A Mystery Man Writer
This video explains what the transformation matrix is to rotate 90 degrees anticlockwise (or 270 degrees clockwise) about the origin.
What would the points (-2, -3) be if you rotated it 90° clockwise? - Quora
Rotating matrices - The DO Loop
image rotation
What is the matrix for the rotation, when the point p (3,-5) is rotating through angle 60 anticlockwise about the origin? - Quora
A-Level Further Maths: C3-21 3D Matrices: Rotation of 90 degrees anticlockwise about the x-axis
90 Degree Anticlockwise Rotation Rotation of Point through 90° about the Origin
Computer Graphics Rotation - javatpoint
Creating a rotation matrix in NumPy
90 Degree Anticlockwise Rotation Transformation Matrix
Rotate Image by 90 degree - GeeksforGeeks