Answer:
[tex]P(x) = x^3 - 10x^2+ 34x-40[/tex]
Step-by-step explanation:
Given
[tex]p =1[/tex] -- Leading coefficient
[tex]Zeros: 4\ and\ 3 - i[/tex]
Required
Determine the polynomial
Represent the zeros with a and b
Such that
[tex]a = 4[/tex]
[tex]b = 3 - i[/tex]
The polynomial is:
[tex]P(x) = p * (x - a) * (x - b)[/tex]
[tex]P(x) = 1 * (x - 4) * (x - (3 - i))[/tex]
However, to solve further: We need to symmetrise over 3-i and its conjugate
[tex]P(x) = 1 * (x - 4) * (x - (3 - i))* (x - (3 + i))[/tex]
[tex]P(x) = (x - 4) * (x - (3 - i))* (x - (3 + i))\\\\[/tex]
To define a suitable function, the expression becomes
[tex]P(x) = (x - 4) * ((x - 3)^2+1)[/tex]
[tex]P(x) = (x - 4) * ((x - 3)(x - 3)+1)[/tex]
[tex]P(x) = (x - 4) * (x^2 - 6x + 9+1)[/tex]
[tex]P(x) = (x - 4) * (x^2 - 6x +10)[/tex]
Open bracket
[tex]P(x) = x^3 - 6x^2 +10x - 4x^2 + 24x-40[/tex]
[tex]P(x) = x^3 - 6x^2 - 4x^2+10x + 24x-40[/tex]
[tex]P(x) = x^3 - 10x^2+ 34x-40[/tex]
