def test_cofactor_of_3x3(self):
a = Matrix([[3, 5, 0], [2, -1, -7], [6, -1, 5]])
assert a.minor(0, 0) == -12
assert a.cofactor(0, 0) == -12
assert a.minor(1, 0) == 25
assert a.cofactor(1, 0) == -25
def test_minor_of_3x3(self):
a = Matrix([[3, 5, 0], [2, -1, -7], [6, -1, 5]])
b = a.submatrix(1, 0)
assert b.determinant() == 25
assert a.minor(1, 0) == 25