2D Reflection Matrix Apply

Problem

Reflect a 2D vector v across the line through the origin at angle theta degrees.

The reflection matrix is [[cos(2t), sin(2t)], [sin(2t), -cos(2t)]] with t = radians(theta).

Hint

theta = 0 reflects across the x-axis; theta = 45 swaps coordinates.

case 1

in: [[1,1],90]

expected: [-1,1]

case 2

in: [[1,0],0]

expected: [1,0]

case 3

in: [[0,2],0]

expected: [0,-2]

case 4

in: [[1,1],45]

expected: [1,1]

Starter codePython

def reflect_2d(v, theta_degrees):
    # Your code here
    pass

4 test cases · run your code against them in the editor