Theorem (For a converging sequence). Assume that [Graphics:Images/FixedPointProof_gr_23.gif] is a continuous function and that [Graphics:Images/FixedPointProof_gr_24.gif] is a sequence generated by fixed point iteration.

If  [Graphics:Images/FixedPointProof_gr_25.gif],  then [Graphics:Images/FixedPointProof_gr_26.gif] is a fixed point of [Graphics:Images/FixedPointProof_gr_27.gif].  

Proof.

If  [Graphics:../Images/FixedPointProof_gr_28.gif],  then  [Graphics:../Images/FixedPointProof_gr_29.gif].  

It follows from this, and the continuity of  [Graphics:../Images/FixedPointProof_gr_30.gif],  and the relation  [Graphics:../Images/FixedPointProof_gr_31.gif]  that

    [Graphics:../Images/FixedPointProof_gr_32.gif].  

Therefore, [Graphics:../Images/FixedPointProof_gr_33.gif] is a fixed point of [Graphics:../Images/FixedPointProof_gr_34.gif].  

Q. E. D.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) John H. Mathews 2004