Finding the Derivative of sin(x)cos(x)

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SUMMARY

The discussion focuses on finding the derivative of the function sin(x)cos(x) using the product rule and trigonometric identities. The correct derivative is derived as y' = cos(2x), achieved by applying the identity sin(2x) = 2sin(x)cos(x) to simplify the calculation. Participants confirm that using the trigonometric identity is the most efficient method, negating the need for partial differentiation in this context.

PREREQUISITES
  • Understanding of trigonometric identities, specifically sin(2x) = 2sin(x)cos(x)
  • Knowledge of the product rule for differentiation
  • Familiarity with basic calculus concepts, including derivatives
  • Ability to perform algebraic simplifications
NEXT STEPS
  • Study the application of the product rule in calculus
  • Learn more about trigonometric identities and their uses in differentiation
  • Explore alternative methods for finding derivatives, such as implicit differentiation
  • Practice problems involving derivatives of trigonometric functions
USEFUL FOR

Students studying calculus, particularly those focusing on differentiation techniques, and educators looking for effective methods to teach trigonometric derivatives.

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Homework Statement



partial derivative (d/dx) sin(x)cos(x)

Homework Equations



Partial Derivatives, product rule

The Attempt at a Solution



sin(2x) = 2 sin x cos x, therefore y=sin(2x)/2

so y'=cos(2x)*(2/2) = cos (2x)?

Is this correct?
Is there an easier way of directly finding the derivative without using substitution?
 
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I don't see why you would be using partial differentiation with this problem? It is not a product of two variables?

No, that's the quickest method. Use the trig identity to avoid product rule.

Either way, GOOD JOB!
 
Last edited:

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