Let [tex]\( f(x) \)[/tex] be a polynomial function with a zero of multiplicity 1 at 4 and a zero of multiplicity 2 at 1. Let [tex]\( g(x) \)[/tex] be the radical function [tex]\( g(x)=\sqrt[3]{x}-4 \)[/tex].

Part A:
Using the Factor Theorem, determine the polynomial function [tex]\( f(x) \)[/tex] in expanded form. Show all necessary calculations. (5 points)



Answer :

To determine the polynomial function [tex]\( f(x) \)[/tex] with the given zeros and their multiplicities, we will use the Factor Theorem. Let's go through the steps:

### Step-by-Step Solution

1. Identify the given zeros and their multiplicities:
- Zero at [tex]\( x = 4 \)[/tex] with a multiplicity of 1.
- Zero at [tex]\( x = 1 \)[/tex] with a multiplicity of 2.

2. Form the polynomial using the zeros and their multiplicities:
According to the Factor Theorem, if [tex]\( r \)[/tex] is a root of a polynomial [tex]\( f(x) \)[/tex] with a multiplicity [tex]\( m \)[/tex], then [tex]\( (x - r)^m \)[/tex] is a factor of [tex]\( f(x) \)[/tex].

Therefore, given the zeros and their multiplicities:
[tex]\[ f(x) = (x - 4)^1 \cdot (x - 1)^2 \][/tex]

3. Expand the polynomial:
- First, expand [tex]\((x - 1)^2\)[/tex]:
[tex]\[ (x - 1)^2 = (x - 1)(x - 1) = x^2 - 2x + 1 \][/tex]

- Next, multiply by [tex]\((x - 4)\)[/tex]:
[tex]\[ f(x) = (x - 4)(x^2 - 2x + 1) \][/tex]

- Now, perform the multiplication:
- Distribute [tex]\( x - 4 \)[/tex] across [tex]\( x^2 - 2x + 1 \)[/tex]:
[tex]\[ f(x) = x(x^2 - 2x + 1) - 4(x^2 - 2x + 1) \][/tex]

- Calculate each term:
[tex]\[ x \cdot (x^2 - 2x + 1) = x^3 - 2x^2 + x \][/tex]
[tex]\[ -4 \cdot (x^2 - 2x + 1) = -4x^2 + 8x - 4 \][/tex]

- Combine the terms:
[tex]\[ f(x) = x^3 - 2x^2 + x - 4x^2 + 8x - 4 \][/tex]

- Simplify by combining like terms:
[tex]\[ f(x) = x^3 - 6x^2 + 9x - 4 \][/tex]

### Final Result
The polynomial function [tex]\( f(x) \)[/tex] in expanded form is:
[tex]\[ f(x) = x^3 - 6x^2 + 9x - 4 \][/tex]

So, the polynomial function [tex]\( f(x) \)[/tex] that has a zero at [tex]\( 4 \)[/tex] with multiplicity 1 and a zero at [tex]\( 1 \)[/tex] with multiplicity 2 is [tex]\( x^3 - 6x^2 + 9x - 4 \)[/tex].