Lill's Method for Calculating the Value of a Cubic Polynomial
Lill's Method for Calculating the Value of a Cubic Polynomial
This Demonstration shows Lill's graphic method for calculating the value of a cubic polynomial using the Horner formulas:
P(x)=a+b+cx+d
3
x
2
x
KK'=ax
LK'=ax+b
LL'=(ax+b)x
ML'=(ax+b)x+c
MM'=((ax+b)x+c)x
and finally,
NM'=((ax+b)x+c)x+d
This is true by Thales's side-splitter theorem. For instance , .
x:1=LL':LK'
LL'=xLK'