Can I Add Sine and Cosine Functions with a Non-Factorable Scalar?

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SUMMARY

The discussion focuses on the mathematical challenge of adding sine and cosine functions with non-factorable scalars. Specifically, the example provided is 5*cos(wt) + 6*cos(wt + π/4). The solution involves expanding cos(wt + π/4) using the cosine addition formula and then grouping like terms. This allows for the expression to be rewritten in the form R*cos(wt ± A) or R*sin(wt ± A), facilitating the addition of the functions.

PREREQUISITES
  • Understanding of trigonometric identities, particularly cosine addition formulas.
  • Familiarity with scalar multiplication in trigonometric functions.
  • Knowledge of how to manipulate and simplify trigonometric expressions.
  • Basic algebra skills for grouping and combining like terms.
NEXT STEPS
  • Study the cosine addition formula in detail, specifically cos(A + B) = cos(A)cos(B) - sin(A)sin(B).
  • Practice rewriting trigonometric expressions in the form R*cos(wt ± A) or R*sin(wt ± A).
  • Explore examples of adding trigonometric functions with different coefficients and phases.
  • Learn about the graphical representation of sine and cosine functions to visualize their addition.
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Students studying trigonometry, mathematicians tackling higher-level problems, and educators looking for examples of trigonometric function manipulation.

mutzy188
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Homework Statement



Hi guys,

I don't know if this should go here because it is an excerpt from a higher level problem. The part where I get stuck is when I try to add the cosine functions.

Is there any way to add sine and cosine functions that have a scalar in front that cannot be factored out? For example:

5*cos(wt) + 6*cos(wt + pi/4)

If there weren't any numbers in front of the functions then I could use the trig identity. What can I do with the numbers there? Thanks
 
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5cos(wt) + 6*cos(wt + π/4)


expand out cos(wt+π/4) then group the like terms. Then you can either put in the form Rcos(wt±A) or Rsin(wt±A)
 
cos(A+ B)= cops(A)cos(B)- sin(A)sin(B).
 

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