How to Integrate by Parts Twice for e^3x cos(x)?

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SUMMARY

The discussion focuses on the integration of the function e^{3x} cos(x) using the technique of integration by parts, specifically applied twice. The user successfully derives the integral as \int e^{3x} \cos{(x)}\; dx = \frac{e^{3x}\sin{(x)} + 3e^{3x} \cos{(x})} {10}. This solution confirms the correct application of integration by parts, demonstrating the method's effectiveness in handling products of exponential and trigonometric functions.

PREREQUISITES
  • Understanding of integration techniques, specifically integration by parts.
  • Familiarity with exponential functions and trigonometric functions.
  • Basic knowledge of calculus, particularly indefinite integrals.
  • Ability to manipulate algebraic expressions involving exponentials and trigonometric identities.
NEXT STEPS
  • Study the integration by parts formula and its applications in various contexts.
  • Practice integrating other combinations of exponential and trigonometric functions.
  • Explore the use of integration by parts in solving differential equations.
  • Learn about the Laplace transform as an alternative method for integrating functions involving exponentials and trigonometric functions.
USEFUL FOR

Students preparing for calculus exams, particularly those focusing on integration techniques, as well as educators seeking to reinforce concepts of integration by parts in their curriculum.

Klion
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I am studying for a midterm, was browsing over an old midterm and found this question


<br /> \int e^{3x} \cos{(x)}\; dx <br />

Can't figure it out, help would be appreciated
 
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Integrate by parts twice. Post back if you get stuck.
 
erm didn't think we'd gotten that far, assignment on that section isn't due until monday. No wonder I couldn't find it hehe.

O well I have 2 hrs to learn it I'm good! :)
 
hmm I ended up with

<br /> \int e^{3x} \cos{(x)}\; dx = \frac{e^{3x}\sin{(x)} + 3e^{3x} \cos{(x})} {10}<br />

that sound about right?
 
Looks good to me.
 

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