Sum-difference trig identity help

  • Context: Undergrad 
  • Thread starter Thread starter volican
  • Start date Start date
  • Tags Tags
    Identity Trig
Click For Summary

Discussion Overview

The discussion revolves around the simplification of a trigonometric expression related to an engineering problem, specifically examining whether it can be expressed using sum-difference formulas from trigonometric identities.

Discussion Character

  • Technical explanation, Debate/contested, Mathematical reasoning

Main Points Raised

  • One participant presents an equation in the form of x = (A * cosα * sinθ) + (B * sinα * cosθ) and seeks simplification using trigonometric identities.
  • Another participant suggests that the expression 2 cos α sin θ could be rewritten as sin(α + θ) + sin(-α + θ), proposing a different compact expression.
  • One participant notes that if |A|=|B|, the expression can be simplified further.
  • Another participant counters that the condition of |A|=|B| is not necessary for simplification.

Areas of Agreement / Disagreement

Participants express differing views on the necessity of the condition |A|=|B| for simplification, indicating that multiple competing views remain in the discussion.

Contextual Notes

The discussion does not resolve the mathematical steps involved in the proposed simplifications or the implications of the coefficients A and B.

volican
Messages
41
Reaction score
0
Hi,

I am working on an engineering problem and I have an equation which takes the following form:

x = (A * cosα * sinθ) + (B * sinα * cosθ)

Can this be further simplified? It almost looks like one of the sum-difference formulas you find in tables of trigonometric identities. I'm not to sure about the different coeffieints though. Any help would be much apreciated.
 
Mathematics news on Phys.org
##2 \cos \alpha \sin \theta = \sin(\alpha + \theta) + \sin(-\alpha+\theta)## could be interesting. Not sure if the result is "simplified", but it is at least a different compact expression.
 
If |A|=|B|, he expression can be simplified.
 
That condition is not necessary.
 

Similar threads

Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
3
Views
3K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 1 ·
Replies
1
Views
5K