Trig and double angle integration

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SUMMARY

The integral ∫sin(t)cos(2t)dt can be simplified using the identity cos(2t) = 1 - 2sin²(t). By substituting this identity into the integral, it becomes ∫sin(t)(1 - 2sin²(t))dt. The discussion highlights that using the alternative identity cos(2t) = 2cos²(t) - 1 allows for a straightforward u-substitution with u = cos(t), leading to a more manageable integration process.

PREREQUISITES
  • Understanding of trigonometric identities, specifically cos(2t) transformations.
  • Familiarity with integration techniques, including substitution and integration by parts.
  • Knowledge of basic calculus concepts, particularly integration of trigonometric functions.
  • Experience with manipulating algebraic expressions in integrals.
NEXT STEPS
  • Study the derivation and application of trigonometric identities in integration.
  • Learn advanced integration techniques, focusing on u-substitution methods.
  • Explore integration of products of trigonometric functions, particularly using identities.
  • Practice solving integrals involving multiple trigonometric identities for deeper understanding.
USEFUL FOR

Students studying calculus, particularly those focusing on integration techniques, as well as educators looking for examples of trigonometric integration methods.

banshee43
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Homework Statement


∫sin(t)cos(2t)dt


Homework Equations


cos(2t)=1-2sin^2(t)


The Attempt at a Solution


∫sint(t)(1-2sin^2(t))dt
but where do i go from here? i can't use substitution. or parts?
 
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cos2x can also = 2cos2x-1, if you make it that, then this is a simple u-substitution..
u=cosx
 
thankyou very much! i just didnt exhaust my formulas..
 

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