Factoring a complex polynomial

In summary, the two equivalent complex equations attached include one written as a polynomial with 7 terms and the other in factored form. To immediately write the factored form based on the 7-term equation, one can use the method of finding the roots of unity, which are multiples of the angle ##\frac{2 \pi}{n}## and are equally distributed along the unit circle. These roots are also known as roots of unity and are given by ##\exp (i{\frac{k}{n} 2 \pi}) ## with ##k=0,\dots ,n-1##.
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TheCanadian
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I've attached two equivalent complex equations, where one is written as a polynomial with 7 terms and the other is the factored form. I was just wondering how one can immediately write down the factored form based on the equation with 7 terms? Is there anything obvious (e.g. coefficient 1) or any particular method (possibly a general one) a person can use to find the factored form of the polynomial?
 

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TheCanadian said:
I've attached two equivalent complex equations, where one is written as a polynomial with 7 terms and the other is the factored form. I was just wondering how one can immediately write down the factored form based on the equation with 7 terms? Is there anything obvious (e.g. coefficient 1) or any particular method (possibly a general one) a person can use to find the factored form of the polynomial?
##1+z+z^2+\dots +z^{n-1} = \frac{z^n - 1}{z-1}##. I.e. the roots of ##z^n-1## are ##1## plus the roots of ##1+z+z^2+\dots +z^{n-1}##. They are called roots of unity (##z^n = 1 ##) and are equally distributed along the unit circle, starting at ##(1,0)##. Therefore they are multiples of the angle ##\frac{2 \pi}{n}##, i.e. ##\exp (i{\frac{k}{n} 2 \pi}) ## with ##k=0,\dots ,n-1##.
 
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What is factoring a complex polynomial?

Factoring a complex polynomial means breaking down a polynomial with complex coefficients into simpler terms. This is done by finding the roots or solutions of the polynomial, which are the values of the variables that make the polynomial equal to zero.

Why is factoring a complex polynomial important?

Factoring a complex polynomial is important because it helps us solve equations, find intercepts, and simplify expressions. It also allows us to understand the behavior and properties of a polynomial better.

What are the steps involved in factoring a complex polynomial?

The steps involved in factoring a complex polynomial include grouping, factoring out the greatest common factor, and using techniques such as the quadratic formula, completing the square, or the difference of squares method to factor the remaining terms.

What are some common techniques used in factoring a complex polynomial?

Some common techniques used in factoring a complex polynomial include the quadratic formula, completing the square, and the difference of squares method. Other techniques include factoring by grouping, factoring by substitution, and factoring by trial and error.

How do I know if a complex polynomial can be factored?

A complex polynomial can be factored if it has at least two terms and each term has a variable with an exponent greater than or equal to 1. If the polynomial cannot be factored, it is called a prime polynomial. In some cases, a polynomial can be factored further using more advanced techniques such as the rational roots theorem or the sum/difference of cubes formula.

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