Trigonometric Identities Section

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SUMMARY

The forum discussion revolves around solving the trigonometric equation 3sin(x) = 1 + cos(2x). The transformation using the trigonometric identity for cos(2x) leads to the equation 2sin²(x) + 3sin(x) - 2 = 0. The solutions to this equation are x = 30° and x = 150°, as confirmed by the original poster's textbook. The discussion highlights the importance of recognizing and applying trigonometric identities in solving equations.

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  • Familiarity with solving quadratic equations
  • Knowledge of the unit circle and angle measures in degrees
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  • Study the derivation and application of trigonometric identities, particularly cos(2x)
  • Practice solving quadratic equations in trigonometric contexts
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Students studying trigonometry, educators teaching trigonometric identities, and anyone looking to enhance their problem-solving skills in trigonometric equations.

Paomaui
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Homework Statement



3sinx = 1 + cos 2x


Homework Equations



N/A

The Attempt at a Solution



3sinx = 1+1 - 2sin2x (Trigonometric Identity)
3sinx = 2-2sin2x
2sin2x + 3sinx = 2

I do not know where to go from there.
My book tells me the answer is 30o and 150o
 
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What happens when you take 2 away from both sides?
 

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