Math Problem Statement

x^6+x^3-2=0

Solution

The equation is x6+x32=0x^6 + x^3 - 2 = 0.

Let's solve this step by step.

  1. Substitute y=x3y = x^3 to simplify the equation: y2+y2=0y^2 + y - 2 = 0 This is now a quadratic equation in terms of yy.

  2. Solve the quadratic equation using the quadratic formula: y=b±b24ac2ay = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} where a=1a = 1, b=1b = 1, and c=2c = -2.

    y=1±124(1)(2)2(1)=1±1+82=1±92y = \frac{-1 \pm \sqrt{1^2 - 4(1)(-2)}}{2(1)} = \frac{-1 \pm \sqrt{1 + 8}}{2} = \frac{-1 \pm \sqrt{9}}{2} y=1±32y = \frac{-1 \pm 3}{2}

    So, y=1y = 1 or y=2y = -2.

  3. Now, substitute back y=x3y = x^3:

    • If x3=1x^3 = 1, then x=1x = 1.
    • If x3=2x^3 = -2, solve x=23x = \sqrt[3]{-2}. The solutions are: [ x = \sqrt[3]{-2}, \quad x = \sqrt[3]{-2} \cdot e^{i 2\pi/3}, \quad x = \sqrt[3]{-2} \cdot e^{i 4\pi/3}. ] These are the three cube roots of 2-2.

Final Solutions:

  1. x=1x = 1
  2. x=23x = \sqrt[3]{-2}
  3. x=23ei2π/3x = \sqrt[3]{-2} \cdot e^{i 2\pi/3}
  4. x=23ei4π/3x = \sqrt[3]{-2} \cdot e^{i 4\pi/3}

Would you like to go deeper into the complex roots or need a different explanation?


Here are 5 related questions to expand:

  1. How do you find cube roots of complex numbers?
  2. Can we solve similar higher-degree polynomial equations?
  3. What are the properties of complex numbers used in solving this?
  4. How does the quadratic formula apply in non-real solutions?
  5. Can this method be generalized for higher powers of xx?

Tip: Always look for ways to simplify higher degree equations by substituting intermediate variables.

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Math Problem Analysis

Mathematical Concepts

Algebra
Polynomials
Substitution
Cube Roots
Complex Numbers

Formulas

Quadratic equation formula: y = (-b ± √(b^2 - 4ac)) / 2a
Cube root solutions: x^3 = k, x = k^(1/3) * e^(i 2πn / 3)

Theorems

Quadratic Formula
Properties of Cube Roots
Complex Roots

Suitable Grade Level

Grades 11-12