Newton’s backward difference table
x 1 1.5 2 2.5 3
f(x) 1 0.5 1.3 0.8 1.5
∇ -0.5 0.8 -0.5 0.7
∇2 1.3 -1.3 1.2
∇3 -2.6 2.5
∇4 5.1
f(x)=yn(x)+p∇yn(x)+2!p(p+1)∇2yn(x)+3!p(p+1)(p+2)∇3yn(x)+4!p(p+1)(p+2)(p+3)∇4yn(x)....whereip=hx−x0p=0.52.8−3p=−0.4,iyn=1.5;i∇yn(x)=0.7;i∇2yn(x)=1.2;i∇3yn(x)=2.5;∇4yn(x)=5.1f(2.8)=1.5+(−0.4)0.7+2!(−0.4)(−0.4+1)1.2+3!(−0.4)(−0.4+1)(−0.4+2)2.5+4!(−0.4)(−0.4+1)(−0.4+2)(−0.4+3)5.1f(2.8)=1.5−0.28−0.144−0.16−0.21216f(2.8)=0.70384
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