HardCalculusca-320

2x2 Determinant Gradient via Adjugate

Problem

For det(A) with A = [[a, b], [c, d]], the gradient with respect to A is the adjugate [[d, -c], [-b, a]].

Given the four entries, return the 2x2 gradient.

Hint

Each partial derivative is the cofactor of the matching entry.

case 1

in: [1,2,3,4]

expected: [[4,-3],[-2,1]]

case 2

in: [0,1,1,0]

expected: [[0,-1],[-1,0]]

case 3

in: [2,-1,4,3]

expected: [[3,-4],[1,2]]

Starter codePython

def determinant_gradient_adjugate(a, b, c, d):
    # Your code here
    pass

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