Culegere de probleme de Analiz˘a numeric˘a
Culegere de probleme de Analiz˘a numeric˘a
Culegere de probleme de Analiz˘a numeric˘a
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
6.5. Interpolare rat¸ională 95<br />
a3 = − 1<br />
a4 = 0 a5 =<br />
6<br />
1<br />
a6 = 0<br />
120<br />
Se obt¸in următorii coeficient¸i:<br />
x7 : a0q6 +a1q5 +a2q4 +a3q3 +a4a2 +a5q1 +a6q0 −p6 = 0<br />
x 6 : q5 − 1<br />
6 q3 + 1<br />
120 q1 = 0<br />
x 5 : a1q4 +a3q2 +a5q0 −p5 = q4 − 1<br />
6 q2 + 1<br />
120<br />
x 4 : a1q3 +a3q1 −p4 = q3 − 1<br />
6 q1 = 0<br />
x 3 : a1q2 +a3q0 −p3 = q2 − 1<br />
6 −p3 = 0<br />
x 2 : a1q1 −p2 = q1 −p2 = 0<br />
x 1 : a0q1 +a1q0 −p1 = 1−p1 = 0<br />
x 0 : a0q0 −p0 = 0<br />
p0 = 0 p1 = 1 q1 = p2 = 0<br />
q3 = 0 q2 = 1<br />
p3 = q2 − 20 1<br />
6<br />
r(x) =<br />
1 1 = − 20 6<br />
= − 7<br />
60<br />
x− 7<br />
60 x3<br />
1+ 1<br />
20 x2<br />
Problema 6.5.3 Dându-sef(0) = 1, f <br />
1 2 1<br />
= , f(1) = , <strong>de</strong>terminat¸i o funct¸ie<br />
2 3 2<br />
F <strong>de</strong> interpolare rat¸ională pentruf.<br />
Solut¸ie.<br />
F = Pr<br />
Ps<br />
m = r +s<br />
f(xi) = f(xi) i = 0,m<br />
fm(x) = f(x0)+<br />
v1(x1)+<br />
v2(x2)+<br />
vi(xi) - diferent¸ele divizate inverse<br />
M = {xi|xi ∈ R, i = 0,m}, xi = xj (i = j)<br />
f : M → R<br />
[x0,x1,...,xk−1,xk;f] − =<br />
= 0<br />
x−x0<br />
x−x1<br />
x−v2<br />
v3(x3)+<br />
. ..<br />
+ x−xm−1<br />
vm(xm)<br />
xkxk−1<br />
[x0,...,xk−2,xk;f] − −[x0,...,xk−1;f] −<br />
[x0,x1;f] − = [x0,x1;f] −1