Can you Simplify the Trigonometric Expression: cos 4x + cos 3x/ sin4x - sin 3x?

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Discussion Overview

The discussion revolves around simplifying the trigonometric expression \( \frac{\cos 4x + \cos 3x}{\sin 4x - \sin 3x} \). Participants explore various approaches to manipulate the expression, focusing on trigonometric identities and expansions.

Discussion Character

  • Exploratory, Technical explanation, Homework-related, Mathematical reasoning

Main Points Raised

  • One participant presents the expression and requests verification against a book answer of \( \cot \left( \frac{x}{2} \right) \).
  • Another participant questions the initial request for checking, suggesting that the poster should first expand the trigonometric functions into terms of \( \cos(x) \) and \( \sin(x) \).
  • A participant proposes rewriting the expression as \( \frac{\cos(4x + 3x)}{\sin(4x + 3x)} \), indicating a potential simplification.
  • There is a question about whether the variable \( x \) needs to be factored out, indicating uncertainty about the approach.
  • Another participant suggests using the sum formulas for sine and cosine to rewrite \( \cos(4x) \) as \( \cos(3x + x) \), hinting at a method for simplification.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best method for simplification, and multiple approaches are proposed without agreement on a definitive solution.

Contextual Notes

Participants reference trigonometric identities and formulas, but there is no resolution on the necessary steps or assumptions required for simplification.

Cutie13
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cos 4x + cos 3x/ sin4x - sin 3x
Please somebody check this over!

The answer in the book is: cot (x/2)
 
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What do you mean by check this over? You've not done anything yet! Try expanding the trigonometric functions so that they end up in terms of cos(x) and sin(x).
 
cos (4x+3x)
____________
sin (4x+3x)
 
or does the x have to be fatored out also?
am i on right track
 
No. Have you come across formulae, for general a and b, for sin(a+b) and cos(a+b)? If so, try writing cos(4x) as cos(3x+x).
 

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