Math Problem Statement
Solution
The question asks to determine the possible number of positive and negative real zeros of the polynomial function:
To determine the possible numbers of positive and negative real zeros, we use Descartes' Rule of Signs. This rule provides a method to estimate the number of positive and negative real roots of a polynomial based on the sign changes in the polynomial's terms.
1. Positive Real Zeros:
For positive real zeros, we analyze the sign changes in .
The function is:
The signs of the coefficients are: .
Count the number of sign changes:
- From to : no sign change.
- From to : one sign change.
- From to : no sign change.
So, there is 1 sign change, meaning there is 1 possible positive real root.
2. Negative Real Zeros:
For negative real zeros, we substitute into and analyze the sign changes in .
Substitute into the polynomial:
This becomes:
The signs of the coefficients are: .
Count the number of sign changes:
- From to : one sign change.
- From to : no sign change.
- From to : one sign change.
So, there are 2 sign changes, meaning there are either 2 or 0 negative real roots.
Conclusion:
According to Descartes' Rule of Signs:
- There is 1 possible positive real root.
- There are either 2 or 0 negative real roots.
Now, let's match this to the answer choices provided:
- Option B: "One positive and two negative roots" is the correct answer based on Descartes' Rule of Signs.
Do you want further details on this, or have any questions?
Here are 5 related questions to explore:
- What is Descartes' Rule of Signs, and how does it work?
- How can synthetic division be used to find exact roots after estimating them?
- Can complex numbers be real roots in some cases, and how would that change the analysis?
- How can the Rational Root Theorem assist in identifying specific roots?
- What are the implications of a polynomial having no real roots?
Tip: Descartes' Rule of Signs gives only the possible number of real roots; the exact number requires further testing or factoring.
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Math Problem Analysis
Mathematical Concepts
Polynomials
Descartes' Rule of Signs
Zeros of Functions
Formulas
Descartes' Rule of Signs: Analyze sign changes in f(x) and f(-x) to estimate real zeros
Theorems
Descartes' Rule of Signs
Suitable Grade Level
Grades 11-12
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