Simplification and manipulation

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Discussion Overview

The discussion revolves around the possibility of factoring the expression involving \(a^2 - b^2\) within a specific mathematical context. Participants explore the implications of this factorization, particularly when \(a\) equals \(b\), and whether algebraic manipulation can resolve any issues that arise from this condition.

Discussion Character

  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant, 'nap', questions whether it is possible to factor out \(a^2 - b^2\) and notes that the equation becomes invalid if \(a = b\).
  • Another participant, Dan, acknowledges the identity \(a^2 - b^2 = (a + b)(a - b)\) but suggests that 'nap' may be looking for a different approach and requests the full problem for clarity.
  • A third participant reiterates the difference of squares identity and emphasizes its importance for efficiency in problem-solving.
  • A later reply points out that the original expression is undefined when \(a = b\) and clarifies that algebraic manipulations will not resolve this issue, suggesting that it is not a removable singularity.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of factoring out \(a^2 - b^2\) and whether algebraic manipulation can address the undefined nature of the expression when \(a = b\). The discussion remains unresolved regarding the best approach to handle this situation.

Contextual Notes

There are limitations in the discussion regarding the assumptions made about the expression and the implications of \(a = b\). The full context of the original problem is not provided, which may affect the analysis.

mathnap7
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Hi All,

I've been stuck on a problem and after much simplification, it has been reduced to the following:

Is it possible to factor out the (a^2 - b^2) bit. For example, if a = b, the equation would not be valid. Is there any way to factor it out using manipulation?

Best wishes,

'nap
 
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mathnap7 said:
Hi All,

I've been stuck on a problem and after much simplification, it has been reduced to the following:

Is it possible to factor out the (a^2 - b^2) bit. For example, if a = b, the equation would not be valid. Is there any way to factor it out using manipulation?

Best wishes,

'nap
Well [math]a^2 - b^2 = (a + b)(a - b)[/math] but it sounds like you are after something different. Can you post the whole problem?

-Dan
 
mathnap7 said:
Hi All,

I've been stuck on a problem and after much simplification, it has been reduced to the following:

Is it possible to factor out the (a^2 - b^2) bit. For example, if a = b, the equation would not be valid. Is there any way to factor it out using manipulation?

Best wishes,

'nap

This is a relatively common expression known as the difference of two squares and is well worth committing to memory to save time

$$a^2-b^2 = (a-b)(a+b)$$
 
Apologies, I am not too familiar with using the LaTeX plugin.

\frac{a^2b^3}{2(a^2-b^2)}\frac{(cos\phi -1)}{(a^2sin^2\phi +b^2cos^2\phi}
 
The expression is
\[
\frac{a^2b^3}{2(a^2-b^2)}\cdot\frac{\cos\phi -1}{a^2\sin^2\phi +b^2\cos^2\phi}
\]
Is there a problem in leaving it like this?

Is it possible to factor out the (a^2 - b^2) bit. For example, if a = b, the equation would not be valid. Is there any way to factor it out using manipulation?
The original expression is indeed undefined when $a=b$, and it is not just a removable singularity. Algebraic manipulations will not make it defined when $a=b$.

It may indeed help if you post the whole problem.
 

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