Example 8. Compare
the "discrete interpolation polynomial" and "Legendre series
approximation," on the interval
.
8 (a). Use the
function
.
Solution 8 (a).
![[Graphics:../Images/LegendrePolyMod_gr_327.gif]](../Images/LegendrePolyMod_gr_327.gif)
![[Graphics:../Images/LegendrePolyMod_gr_328.gif]](../Images/LegendrePolyMod_gr_328.gif)
Details for this computation.
First, construct the coefficients.
![[Graphics:../Images/LegendrePolyMod_gr_330.gif]](../Images/LegendrePolyMod_gr_330.gif)
Construct the terms.
![[Graphics:../Images/LegendrePolyMod_gr_332.gif]](../Images/LegendrePolyMod_gr_332.gif)
![[Graphics:../Images/LegendrePolyMod_gr_333.gif]](../Images/LegendrePolyMod_gr_333.gif)
Then add up the terms.
![[Graphics:../Images/LegendrePolyMod_gr_335.gif]](../Images/LegendrePolyMod_gr_335.gif)
(c) John H. Mathews 2005