EasyCalculusca-257

Inverse Polar Jacobian Determinant

Problem

The inverse polar map (x, y) -> (r, theta) has Jacobian determinant 1 / sqrt(x^2 + y^2).

Given x and y not both zero, return that determinant. Return None at the origin, where the map is singular.

Hint

This determinant is the reciprocal of the forward polar Jacobian determinant r.

case 1

in: [3,4]

expected: 0.2

case 2

in: [1,0]

expected: 1

case 3

in: [0,2]

expected: 0.5

case 4

in: [0,0]

expected: null

Starter codePython

def inverse_polar_jacobian(x, y):
    # Return None at the origin
    # Your code here
    pass

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