FastDeploy/third_party/eigen/doc/examples/TutorialLinAlgInverseDeterminant.cpp

#include <Eigen/Dense>
#include <iostream>

using namespace std;
using namespace Eigen;

int main() {
  Matrix3f A;
  A << 1, 2, 1, 2, 1, 0, -1, 1, 2;
  cout << "Here is the matrix A:\n" << A << endl;
  cout << "The determinant of A is " << A.determinant() << endl;
  cout << "The inverse of A is:\n" << A.inverse() << endl;
}