Transcription of ERROR IN LINEAR INTERPOLATION
{{id}} {{{paragraph}}}
ERROR IN LINEAR INTERPOLATIONLetP1(x) be the LINEAR polynomial interpolatingf(x) (x) is twice continuously differentiable on an interval[a,b] which contains the pointsx0<x1. Then fora x b,f(x) P1(x) =(x x0) (x x1)2f (cx)for somecxbetween the minimum and maximum ofx0,x1, usually useP1(x) as an approximation off(x) forx [x0,x1].Then for an ERROR bound,|f(x) P1(x)| (x x0) (x1 x)2maxx0 x x1|f (x)|,x [x0,x1].Easily, withh=x1 x0,maxx0 x x1(x x0) (x1 x) =h2 ,|f(x) P1(x)| h28maxx0 x x1|f (x)|,x [x0,x1].EXAMPLELetf(x) = log10x; and in line with typical tables of log10x, wetake 1 x0 x x1 10, and again leth=x1 x0. Thenf (x) = log10ex2maxx0 x x1|f (x)|= ,|log10x P1(x)| h28log10ex20,x [x0,x1].Typical high school algebra textbooks contain tables of log10xwith a spacing ofh=.
For f(x) = log 10 x, with 1 x 0 x x 2 10; this leads to jlog 10 x P 2(x)j h3 9 p 3 max x0 x x2 2log 10 e x3:05572h3 x3 0 For the case of h = :01, we have jlog 10 x P 2(x)j 5:57 10 8 x3 0 5:57 10 8 For comparison, jlog 10 x P 1(x)j 5:43 10 6
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document:
{{id}} {{{paragraph}}}