Math Problem Statement

Find a polynomial equation with real coefficients that has the given zeros. 3minus2i and 3plus2i

Solution

To find a polynomial with real coefficients that has the given complex roots 32i3 - 2i and 3+2i3 + 2i, we can use the fact that if a polynomial has real coefficients, then the complex roots must occur in conjugate pairs.

Given:

  • Zeros: 32i3 - 2i and 3+2i3 + 2i

Step-by-Step Solution

  1. Write the factors associated with each root: Since 32i3 - 2i and 3+2i3 + 2i are roots, they correspond to the factors: (x(32i))and(x(3+2i))(x - (3 - 2i)) \quad \text{and} \quad (x - (3 + 2i))

  2. Multiply the factors: We want to find the product (x(32i))(x(3+2i))(x - (3 - 2i))(x - (3 + 2i)).

  3. Apply the difference of squares formula: This can be simplified using the identity (ab)(a+b)=a2b2(a - b)(a + b) = a^2 - b^2.

    Let a=x3a = x - 3 and b=2ib = 2i, so: (x(32i))(x(3+2i))=(x3)2(2i)2(x - (3 - 2i))(x - (3 + 2i)) = (x - 3)^2 - (2i)^2

  4. Simplify further: =(x3)24i2= (x - 3)^2 - 4i^2 Since i2=1i^2 = -1, this becomes: =(x3)2+4= (x - 3)^2 + 4

  5. Expand (x3)2(x - 3)^2: (x3)2=x26x+9(x - 3)^2 = x^2 - 6x + 9 So, (x3)2+4=x26x+9+4=x26x+13(x - 3)^2 + 4 = x^2 - 6x + 9 + 4 = x^2 - 6x + 13

Final Answer

The polynomial with real coefficients that has roots 32i3 - 2i and 3+2i3 + 2i is: x26x+13=0x^2 - 6x + 13 = 0

Would you like more details or have any questions?

Here are some related questions:

  1. How do we find the polynomial if the zeros are given as complex conjugates in a different form?
  2. Why must complex roots of polynomials with real coefficients come in conjugate pairs?
  3. How does the difference of squares formula apply to complex conjugate pairs?
  4. Can polynomials with real coefficients have purely imaginary roots?
  5. How would the equation change if we were given additional real roots?

Tip: Remember, when a polynomial has real coefficients, any complex roots must appear in conjugate pairs to ensure all coefficients remain real.

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Math Problem Analysis

Mathematical Concepts

Algebra
Complex Numbers
Polynomials
Conjugate Pairs

Formulas

(a - b)(a + b) = a^2 - b^2
i^2 = -1
Quadratic form: ax^2 + bx + c = 0

Theorems

Complex Conjugate Root Theorem
Difference of Squares

Suitable Grade Level

Grades 10-12