Hint for HW 2.6

C f' and f" from five-point formulas

C

DO 100 I = 3, N-2

F1(I) = (FI(I-2) - 8.*FI(I-1)+8.*FI(I+1)-FI(I+2))/(12.*H)

F2(I)=(-FI(I-2)+16.*FI(I-1)-30.*FI(I)+16.*FI(I+1)-FI(I+2))

F2(I) = F2(I)/(12.*H*H)

100 CONTINUE

C

C Linear extrapolation for the boundary points

C

F1(2) = 2.*F1(3) - F1(4)

F1(1) = 2.*F1(2) - F1(3)

F1(N-1) = 2.*F1(N-2) - F1(N-3)

F1(N) = 2.*F1(N-1) - F1(N-2)

F2(2) = 2.*F2(3) - F2(4)

F2(1) = 2.*F2(2) - F2(3)

F2(N-1) = 2.*F2(N-2) - F2(N-3)

F2(N) = 2.*F2(N-1) - F2(N-2)