// Polynomes de Lagrange P_1 et ses derivees 
//
function [FP,DxFP]=P1(x)
// 
  FP = zeros(2,1);   DxFP = zeros(2,1); 
//
  FP(1) =  (1-x)/2;
  FP(2) =  (1+x)/2;

  DxFP(1) = -1./2.;
  DxFP(2) =  1./2.;


endfunction


