SOLUTION: A Polynomial Function for Volume The polynomial function given below represents the volume of a rectangular prism with a square base. Each binomial factor of the polynomial repr

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A Polynomial Function for Volume The polynomial function given below represents the volume of a rectangular prism with a square base. Each binomial factor of the polynomial repr      Log On


   



Question 1105250: A Polynomial Function for Volume
The polynomial function given below represents the volume of a rectangular prism with a square base. Each binomial factor of the polynomial represents one dimension of the rectangular prism.
f(x) = x^3 + x^2 – 21x – 45

g(x) is a fourth-degree polynomial function with the following properties.
•g(x) has the same real zeros as f(x).
•g(x) has at least one imaginary zero.
Find a possible equation for g(x). Write your equation in standard form. Enter your answer and explanation in the box.

Found 2 solutions by josgarithmetic, greenestamps:
Answer by josgarithmetic(39623) About Me  (Show Source):
You can put this solution on YOUR website!
Possible roots based on Rational Roots Theorem include -3, +3, -5, +5, and others.
Trying polynomial, OR synthetic division gives this factorization for f:
f%28x%29=%28x-5%29%28x%2B3%29%5E2

Since the description gives that the box has a square base, the side of each base dimension is the x%2B3. Length is x-3 and width is x-3.

The height of the box would be x-5.

Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


f%28x%29+=+%28x-5%29%28x%2B3%29%5E2; its zeros are 5 and -3.

If g(x) is a polynomial of degree 4 with the same real zeros as f(x) and with at least one imaginary root, then it must have single real zeros of 5 and -3 and one pair of imaginary zeros.

With only those restrictions, a possible polynomial g(x) is
g%28x%29+=+%28x-5%29%28x%2B3%29%28x%5E2%2B1%29+=+x%5E4-2x%5E3%2B16x%5E2-2x%2B15