Therefore, cos/(1-tan) + sin/(1-cot) = sin + cos

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SUMMARY

The equation cos/(1-tan) + sin/(1-cot) simplifies to sin + cos through a series of algebraic manipulations. The initial expression is transformed by substituting tan and cot with their sine and cosine equivalents, leading to a common denominator. The final result is achieved by applying the difference of squares identity, confirming the equality. This proof demonstrates the effective use of trigonometric identities and algebraic techniques in simplifying complex expressions.

PREREQUISITES
  • Understanding of trigonometric identities, specifically sine, cosine, tangent, and cotangent.
  • Familiarity with algebraic manipulation techniques, including common denominators and factoring.
  • Knowledge of the difference of squares identity in algebra.
  • Basic skills in simplifying rational expressions.
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  • Study the properties and identities of trigonometric functions, focusing on sine, cosine, tangent, and cotangent.
  • Practice algebraic manipulation techniques, including finding common denominators and factoring expressions.
  • Explore the difference of squares identity and its applications in simplifying expressions.
  • Review additional trigonometric proofs to enhance problem-solving skills in trigonometry.
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Students studying trigonometry, mathematics educators, and anyone looking to improve their skills in algebraic manipulation and trigonometric proofs.

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Trig Question...

Homework Statement


Prove: cos/(1-tan) + sin/(1-cot) = sin + cos



The Attempt at a Solution


Cos/(1-sin/cos) + sin/(1 - cos/sin)

cos/((cos-sin)/cos) + sin/ ((sin - cos)/sin)

cos^2/(cos-sin) +sin^2/(sin-cos)

(cos - sin)(cos+sin)/(cos - sin)^2

(cos + sin)/(cos - sin)
 
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I believe you can manage differently from this step:

cos^2/(cos-sin) +sin^2/(sin-cos)

I have not tried the identity yet. From the step I quoted, you may be able to use cos-sin = -(sin-cos). Try it and see if it allows you something more effective.
 


yes it works... it becomes (sin^2 - cos^2)/(sin -cos)

(sin - cos)(sin + cos)/(sin-cos)
sin + cos
 

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