0 Daumen
293 Aufrufe

wie berechne ich die Schnittstellen von

f(x)=x^3-5*x^2+6*x  und  g(x)=1,75*x+1

ich weiß, dass ich gleichsetzen muss, komme dann aber nicht weiter!

Avatar von

3 Antworten

0 Daumen
 
Beste Antwort

x^3 - 5·x^2 + 6·x = 1.75·x + 1
x^3 - 5·x^2 + 4.25·x - 1 = 0

Eine Nullstelle findest du per Wertetabelle bei 4 und machst eine Polynomdivision

(x^3 - 5·x^2 + 4.25·x - 1)/(x - 4) = x^2 - x + 0.25

Die restliche(n) Nullstelle(n) liefert jetzt die pq-Formel bei x = 0.5.

Avatar von 479 k 🚀

Super!

0 Daumen

Hallo,

gleichsetzen, dann alles auf Null, Polynomdivision durchführen

x³-5x²+6x= 1,75x +1  

x³-5x² +4,25 x -1   = 0    

1/4 (4x³ -20x² +17x -4)

Polynomdivision durchführen mit (x - 4)    , dann pq-Formel anwenden

Lösungen L= { 0,5 , 4} 

     

Avatar von 40 k
0 Daumen

gleichgesetzt f(x)=g(x)

x³-5*x²+6*x=1,75*x+1

0=x³-5*x²+6*x-1,75*x-1

0=x³-5*x²+4,25*x-1 Lösung mit meinem Graphikrechner (GTR,Casio) x1=0,5 und x2=4

Oft sind die Nullstellen keine ganzen Zahlen und dann muß man eine Nullstelle angenähert durch probieren ermitteln und dann den Wert durch einer der beiden Näherungsformeln von

Newton (Tangentenverfahren) oder Regula falsi (Sehenverfahren)

Hier Infos per Bild,vergrößern und/oder herunterladen

Näherungsformeln.JPG

Text erkannt:

"
" A veres, are sen arere nercolor man heranger are and not
in and the reacher and and and and and and and and and and and and and and and and and and and and and and
and and and and and and and and and
perencents and are are are are are are are are are are are are are are are are are are are are are are are are are are are
reacherent and and and and and and and and and and and and and and and and and and and
and and and and and and and and and and
and and and and and and 8 and
and and and 8 and 4 and
and and 8 and 4 and
and and 8 and 4 and
and and 1 and 1 and
and and and 1 and
and and are are are are are
and and 1 and
and and 1 and
and 1 and
and 1 and
and 1 and
and and
and and and
and and and are are are are are are are are are are are
and and and and
and and and
and and
and and and and
and and
Darsing
are
\( \begin{array}{ll}\text { (年) } \frac{1}{3} & \text { (年) } 4,5,5 \\ \text { (年) } \frac{0}{5} & \text { (年) } \frac{0}{5}\end{array} \)
Ind. since and

Avatar von 6,7 k

Ein anderes Problem?

Stell deine Frage

Willkommen bei der Mathelounge! Stell deine Frage einfach und kostenlos

x
Made by a lovely community