Solving for a Cubic Function with Given Points

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SUMMARY

The discussion focuses on finding a cubic function f(x) that satisfies the conditions f(1)=6 and f(-1)=f(0)=f(2)=0. The correct expression for the cubic function is f(x) = a(x + 1)(x)(x - 2), where the factors correspond to the roots of the function at x = -1, 0, and 2. The coefficient "a" is determined using the condition f(1)=6, which ensures the function meets the specified value at x=1. The factor theorem is essential for understanding why these roots are used in constructing the cubic function.

PREREQUISITES
  • Understanding of cubic functions and their properties
  • Knowledge of the factor theorem in polynomial equations
  • Familiarity with evaluating functions at specific points
  • Basic algebraic manipulation skills
NEXT STEPS
  • Study the factor theorem in detail to understand its application in polynomial functions
  • Learn how to determine coefficients in polynomial equations using given function values
  • Explore the characteristics of cubic functions and their graphs
  • Practice solving cubic equations with various sets of conditions
USEFUL FOR

Students studying algebra, particularly those working on polynomial functions and cubic equations, as well as educators seeking to reinforce concepts related to function evaluation and the factor theorem.

brycenrg
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Homework Statement


Find an expression for a cubic function f if f(1)=6 and f(-1)=f(0)=f(2)=0


Homework Equations


I figured it out but I am not sure why we use the equation f(x) = a[x-(-1)](x-0)(x-2)


The Attempt at a Solution


Im assuming its because if u times that equation that is a cubic function, but does it have anything todo with f(-1)=f(0)=f(2)=0 ?
 
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Certainly yes. Those f(c)=0 values mean that some binomial, x-c, is a factor of the function's expression or its definition. Your exercise gives you three of them and they are for a cubic function. The binomial factors will take care of your roots for your function. The coefficient, "a", is for accounting for the remainder in case you choose a value for x which is not a root. The given f(1)=6 helps you to find "a".
 
@brycenbrg: Look up the factor theorem in your text or online.
 

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