3x3 determinant from one cross product and one dot product

	double determinant(const Matrix3d& m)
	{
		// https://textbooks.math.gatech.edu/ila/determinants-volumes.html
		// https://copilot.microsoft.com/chats/qQxM5K1jer1Dc6pMtuDfD

		Vector3d a;
		a(0) = m(0, 0);
		a(1) = m(0, 1);
		a(2) = m(0, 2);

		Vector3d b;
		b(0) = m(1, 0);
		b(1) = m(1, 1);
		b(2) = m(1, 2);

		Vector3d c;
		c(0) = m(2, 0);
		c(1) = m(2, 1);
		c(2) = m(2, 2);

		Vector3d cross = b.cross(c);
		return std::abs(a.dot(cross));
	}