MHB Factoring when exponent is a variable

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The discussion revolves around factoring the expression (x^(1/n) + a)^(n-1), with particular emphasis on the challenges posed by the variable exponent n-1. Participants suggest using the law of exponents to simplify the expression and recommend applying the binomial theorem for further manipulation. There is a focus on the goal of dividing the expression by x and achieving a specific result, x^(1/n) - (n-1)a, while acknowledging that some terms may be ignored for simplicity. The term "factoring" is debated, with clarification that it involves breaking down expressions into lower-degree terms, which is less common in this context. The conversation highlights the need for careful consideration of terms when applying these mathematical techniques.
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
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

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