Finding partial derivative of a trig function

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SUMMARY

The discussion focuses on finding the partial derivative of the function sin(xyz - 1) with respect to x. The correct derivative is yz*cos(xyz - 1), which aligns with the output from Wolfram Alpha, confirming the equivalence of the two expressions. Users clarified that cos(x) is indeed equal to cos(-x), which explains the apparent discrepancy. The importance of utilizing tools like Wolfram Alpha for step-by-step solutions was emphasized.

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  • Understanding of partial derivatives in multivariable calculus
  • Familiarity with trigonometric functions and their properties
  • Basic knowledge of using computational tools like Wolfram Alpha
  • Experience with mathematical notation and expressions
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  • Study the rules of differentiation for multivariable functions
  • Learn about trigonometric identities and their applications in calculus
  • Explore the features of Wolfram Alpha for solving calculus problems
  • Practice finding partial derivatives of various functions
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Students in advanced mathematics courses, particularly those studying calculus and multivariable functions, as well as educators seeking to clarify concepts related to partial derivatives and trigonometric functions.

lagwagon555
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Homework Statement



Find the partial derivative with respect to x of sin(xyz - 1)


Homework Equations



None needed.

The Attempt at a Solution



I took the answer to be yz*cos(xyz - 1), but wolfram alpha is giving me yz*cos(1 - xyz). Anyone know what's going on here? Thanks!
 
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cos(x) is equal to cos(-x)

Those answers are equivalent.

Btw, if you're confused as to what Wolfram Alpha is doing, press the "Show steps" button. Helps out sometimes.
 
Ah right I see, thanks a lot for clarifying that. I'm taking a senior level maths paper after 2 years of not doing maths, so I keep slipping up on things like that. Thanks again :)
 

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