Math Problem Statement

Write a polynomial of least degree with integer coefficients that has the given zeros.

-3,-1+ square root of 3

Leave your answer in factored form, but make sure there are no irrational or imaginary values.

Solution

To construct a polynomial with the given zeros, we need to account for both the given roots and any necessary conjugate roots. The given zeros are 3-3 and 1+3-1 + \sqrt{3}.

Step 1: Include the Conjugate Root

For the zero 1+3-1 + \sqrt{3}, its conjugate 13-1 - \sqrt{3} must also be a root of the polynomial to ensure that the coefficients of the polynomial are integers.

Step 2: Write the Factors

The polynomial will have factors corresponding to each root:

  • For the root 3-3, the factor is (x+3)(x + 3).
  • For the roots 1+3-1 + \sqrt{3} and 13-1 - \sqrt{3}, the factors are (x+13)(x + 1 - \sqrt{3}) and (x+1+3)(x + 1 + \sqrt{3}).

Step 3: Multiply the Conjugate Factors

First, let's multiply the conjugate factors: (x+13)(x+1+3)(x + 1 - \sqrt{3})(x + 1 + \sqrt{3})

This is a difference of squares: (x+1)2(3)2(x + 1)^2 - (\sqrt{3})^2 =(x+1)23= (x + 1)^2 - 3 =x2+2x+13= x^2 + 2x + 1 - 3 =x2+2x2= x^2 + 2x - 2

Step 4: Multiply All Factors

Now, multiply this result by the factor corresponding to the root 3-3: (x+3)(x2+2x2)(x + 3)(x^2 + 2x - 2)

Leave the polynomial in factored form: (x+3)(x2+2x2)\boxed{(x + 3)(x^2 + 2x - 2)}

This is the polynomial of least degree with integer coefficients that has the given zeros.

Would you like to see the polynomial expanded or have any further questions?

Here are 5 related questions:

  1. How do you determine the conjugate of a root that involves square roots?
  2. What is the difference between a polynomial in factored form and expanded form?
  3. Can you explain why the product of conjugates eliminates irrational numbers?
  4. What does the "least degree" of a polynomial mean?
  5. How would the process change if one of the roots were imaginary?

Tip: Always remember to include conjugate pairs when forming polynomials with real coefficients to eliminate any irrational parts.

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Math Problem Analysis

Mathematical Concepts

Algebra
Polynomials
Roots and Zeros

Formulas

Difference of squares formula: (a + b)(a - b) = a^2 - b^2

Theorems

Conjugate Root Theorem

Suitable Grade Level

Grades 10-12