RÉSOLUTION NUMÉRIQUE DES ÉQUATIONS 
209 
Exemple 2. y = x 3 — 4x 2 — 2x + 4 = 0. 
x l — 4,24, y , = — 0,165376 
æ 3 = 4,25, y. 2 = 0,015625 
= 4,249137, y 3 = — 0,000064296413985647 
Valeur trouvée x = 4,2491405381345 
Valeur exacte æ = 4,2491405381295 
D = +0,0000000000050 
5 5 1 
Exemple 3. y = x* — X æ3 yj x — — (} - 
x { = 0,978 , Vi = — 0,000192003873632 
æ 2 = 0,979, y 2 = 0,001113684570899 
æ 3 == 0,9781471, y 3 = — 0,00000065179001782223705 
Valeur trouvée x == 0,9781476007346 
Valeur exacte x — 0,9781476007338 
D= + 0,0000000000008 
Exemple 4. y = x 3 — 5x H- 4 = 0. 
x i = 1,5615, y t == — 0,000122266625 
x 2 = 1,5616, y,= 0,000109264896 
x 3 = 1,561552808, y 3 = — 0,000000011134084491 
Valeur trouvée x = 1,56155281280883032 
Valeur exacte a? = 1,56155281280883027 
1) = + 0,00000000000000005 
Exemple 5. y = x — 10 log 10 x = 0. 
^ = 1,3, v, = 0,160566477 
= 1,4, y 2 = — 0,061280357 
a? 3 = 1,372, y 3 S — 0,001541114 
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