# Finding Expressions

1. Sep 25, 2009

### DrDanger

1. The problem statement, all variables and given/known data

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

2. Relevant equations

3. The attempt at a solution
I tried to graph the points and find an equation for the function, but couldn't.

2. Sep 25, 2009

### Bohrok

Do you know about the relationship between zeros of a function and its factors?

3. Sep 25, 2009

### DrDanger

yeah the factors are the zeros, right?

4. Sep 25, 2009

### Bohrok

Yes. You know what values of x make the function 0, so how do you write the zeros as factors?

5. Sep 26, 2009

### DrDanger

(x+1)(x-2)?

6. Sep 26, 2009

### Bohrok

You have two; what's the last one?

7. Sep 26, 2009

### DrDanger

(x+6) lol I have no idea! I know it involves f(1)=6 though

8. Sep 26, 2009

### Bohrok

If your cubic function has a root at x = 0 ( because f(0) = 0), might you write the factor something like (x + 0)? How would you rewrite that factor and put it with the other two factors?