Understanding the Properties of Imaginary Cube Roots of Unity

In summary, the quadratic equations formed with the roots of x2 + x + 1 = 0 are (i) x2 + x + 1 = 0 and (ii) x2 + x + 1 = 0. The roots have a special property where the square of one root is equal to the other root and the same applies for taking reciprocals.
  • #1
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Homework Statement
Let the roots of x2 + x + 1 = 0 be [itex]\alpha[/itex] and [itex]\beta[/itex], form a quadratic equation with roots:
(i) [itex]\alpha[/itex]2, [itex]\beta[/itex]2; and
(ii) [itex]\frac{1}{\alpha}[/itex], [itex]\frac{1}{\beta}[/itex].The attempt at a solution
sum of roots = [itex]\alpha[/itex] + [itex]\beta[/itex] = -1
product of roots = [itex]\alpha\beta[/itex] = 1

(i)
sum of roots = [itex]\alpha[/itex]2 + [itex]\beta[/itex]2 = (-1)2 - 2(1) = -1
product of roots = [itex]\alpha[/itex]2[itex]\beta[/itex]2 = 12 = 1
Quadratic equation: x2 + x + 1 = 0

(ii)
sum of roots = [itex]\frac{1}{\alpha}[/itex] + [itex]\frac{1}{\beta}[/itex] = [itex]\frac{-1}{1}[/itex] = -1
product of roots = ([itex]\frac{1}{\alpha}[/itex])([itex]\frac{1}{\beta}[/itex]) = 1
Quadratic equation: x2 + x + 1 = 0

Is this weird? Did I do something wrong?
Thanks.
 
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  • #2
correct.
roots of original equations are imaginary cube roots of unity.
which has the property that the square of first root is equal to second root,and square of second root is equal to first root.
the same property for taking reciprocals.
 

FAQ: Understanding the Properties of Imaginary Cube Roots of Unity

1. How do you determine the coefficient of the x^2 term in a quadratic equation?

The coefficient of the x^2 term in a quadratic equation is the number that is multiplied by x^2. In the general form of a quadratic equation, ax^2 + bx + c, the coefficient of the x^2 term is represented by the variable a.

2. What is the process for solving a quadratic equation?

The process for solving a quadratic equation involves finding the values of x that make the equation true. This can be done through factoring, the quadratic formula, or completing the square. Once the values of x are found, they can be used to graph the equation or solve for other variables.

3. How do you know if a quadratic equation has one or two solutions?

A quadratic equation will have one solution if the discriminant, b^2 - 4ac, is equal to 0. This means that the equation has a perfect square as its solution. If the discriminant is greater than 0, the equation will have two distinct solutions. If the discriminant is less than 0, the equation will have no real solutions.

4. Can a quadratic equation have complex solutions?

Yes, a quadratic equation can have complex solutions. This occurs when the discriminant is less than 0, meaning that the solutions involve imaginary numbers. Complex solutions are often represented as a+bi, where a and b are real numbers and i is the imaginary unit.

5. How can I use the quadratic formula to solve a quadratic equation?

The quadratic formula is the formula used to solve any quadratic equation in the form ax^2 + bx + c = 0. It is written as x = (-b ± √(b^2 - 4ac)) / 2a. To use the quadratic formula, simply plug in the values of a, b, and c from the equation into the formula and solve for x using the order of operations.

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