Factoring when exponent is a variable

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Discussion Overview

The discussion revolves around the challenges of factoring the expression $$\large(x^{\frac{1}{n}}+a)^{n-1}$$, particularly when the exponent is a variable. Participants explore various methods and implications of factoring in this context, including potential applications in division and simplification.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants express confusion about how to factor the expression due to the variable exponent, specifically $$n-1$$.
  • One participant suggests using the law of exponents to simplify the expression, indicating that this could facilitate the application of the binomial theorem.
  • Another participant mentions the goal of factoring is to enable division by $$x$$, aiming for a specific result of $$\large x^{\frac{1}{n}}-((n-1)a)$$, while acknowledging that some terms may be ignored in the process.
  • A different approach is proposed by substituting $$u = x^{\frac{1}{n}} + a$$, leading to a transformation of the expression, but still requiring the binomial theorem for further simplification.
  • Several participants question the meaning of "factoring" in this context, suggesting that it is not a typical application for the expression at hand.
  • There is a discussion about the nature of factoring, with examples provided that illustrate traditional factoring methods, which may not directly apply to the current expression.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best approach to factoring the expression. There are differing interpretations of what "factoring" means in this context, and multiple methods are proposed without agreement on their effectiveness.

Contextual Notes

Some participants express uncertainty about the assumptions underlying their approaches, particularly regarding the treatment of terms and the application of the binomial theorem. The discussion highlights a lack of clarity on how to handle variable exponents in factoring.

Vac1
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I am trying to factor the following equation

$$\large(x^{\frac{1}{n}}+a)^{n-1}$$

but the fact that the exponent is n-1 is throwing me off. How could I go about factoring out this equation? Thanks.
 
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Vac said:
I am trying to factor the following equation

$$\large(x^{\frac{1}{n}}+a)^{n-1}$$

but the fact that the exponent is n-1 is throwing me off. How could I go about factoring out this equation? Thanks.

Use the law of exponents to simplify the exponent: $$ \displaystyle \left(x^{\frac{1}{n}}\right)^{n-1} = \left(x^{\frac{1}{n}}\right)^n \cdot \left(x^{\frac{1}{n}}\right)^{-1} $$

The only real advantage I can see to simplifying this expression is to be able to use the binomial theorem on the exponent.
 
The reason I'm trying to factor it is so that I can divide it by x.

$$\large\frac{x}{(x^{\frac{1}{n}}+a)^{n-1}}$$

I'm not concerned with the remainder at all but I'm looking for a result that should be equal to:

$$\large x^{\frac{1}{n}}-((n-1)a)$$

I'm assuming to get this, I'll need to ignore some of the terms in the polynomial when factoring which have less of an influence. Thanks
 
I do not know if this could help you
let x^{\frac{1}{n}} + a = u

\frac{(u-a)^n}{u^{n-1}}
but you still need the binomial theorem as what supersonic said
if you want to ignore the terms with the denominator different from 1
\frac{(u-a)^n}{u^{n-1}}\approx u - na
sub u value and factor -a
 
Last edited:
Vac said:
I am trying to factor the following equation

$$\large(x^{\frac{1}{n}}+a)^{n-1}$$

but the fact that the exponent is n-1 is throwing me off. How could I go about factoring out this equation? Thanks.

What do you mean by "factoring" this expression(not equation). ?? I don't quite understand what exactly you want to do with this expression.
Factoring to me is something like $x^2+5x+6=(x+2)(x+3)$
 
caffeinemachine said:
What do you mean by "factoring" this expression(not equation). ?? I don't quite understand what exactly you want to do with this expression.
Factoring to me is something like $x^2+5x+6=(x+2)(x+3)$

Factoring is essentially splitting an expression into terms each with a lower degree than the original. You could factor 8 as (2)(2)(2) or (2)(4) if you so wanted (this mainly comes up in prime factoring for LCM and GCF).
Alternatively you could factor $x^3-x = x(x^2-1) = x(x-1)(x+1)$

In this case factoring is unusual and the only way I could see it being used is to then use the binomial theorem with appropriate truncation
 

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