the cubic polynomial below has zeroes at x=-4 and x=6 only and passes through the point (2,36) as shown. algebraically determine its equation in factored form. show how you arrived at your answer.



Answer :

Answer:

[tex]f(x)=\dfrac{1}{2}(2x-7)(x+4)(x-6)[/tex]

Step-by-step explanation:

Cubic polynomial in intercept form:

[tex]f(x)=(x-p)(x-q)(x-r)[/tex]

where p, q and r are the zeros.

Given:

  • Zeros at x = -4 and x = 6
  • Passes through the point (2, 36)

Substitute the zeros into the formula:

[tex]f(x)=(x-p)(x+4)(x-6)[/tex]

Substitute the point into the equation and solve for p:

[tex]\implies (2-p)(2+4)(2-6)=36[/tex]

[tex]\implies (2-p)(6)(-4)=36[/tex]

[tex]\implies -24(2-p)=36[/tex]

[tex]\implies 2-p=-\dfrac{3}{2}[/tex]

[tex]\implies p=\dfrac{7}{2}[/tex]

Therefore:

[tex]f(x)=\left(x-\dfrac{7}{2}\right)(x+4)(x-6)[/tex]

Factor out ¹/₂ from the first parentheses:

[tex]f(x)=\dfrac{1}{2}(2x-7)(x+4)(x-6)[/tex]

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