Integrating a Fraction using the product rule

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SUMMARY

The discussion focuses on integrating a complex fraction using the product rule and long division. The initial approach attempted integration by parts, which led to a more complicated integral. Participants recommended breaking the integral into two parts: ∫{\frac{x^3}{16xtanx+sinx}}dx and ∫{\frac{56x^2sin^6x}{16xtanx+sinx}}dx, and emphasized the importance of mastering polynomial long division for simplifying such integrals. The consensus is that while long division may create a challenging integral, it is a necessary skill for solving this type of problem effectively.

PREREQUISITES
  • Understanding of polynomial long division
  • Familiarity with integration techniques, specifically integration by parts
  • Knowledge of trigonometric identities, particularly for tangent and sine functions
  • Basic calculus concepts, including integrals of rational functions
NEXT STEPS
  • Practice polynomial long division with various examples
  • Study integration by parts with complex functions
  • Learn to simplify trigonometric expressions, focusing on tan(x) as sin(x)/cos(x)
  • Explore advanced integration techniques for rational functions
USEFUL FOR

Students studying calculus, particularly those tackling integration of complex fractions, and educators seeking to enhance their teaching methods in integration techniques.

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Homework Statement


Find the integral of
gif.gif

This was the question. There is a way to do it by long division but I am confused with Long division. Instead I tried to do by the method below but I failed...

Homework Equations


None

The Attempt at a Solution


I thought maybe I could reduce the denominator to the power of -1 and then Integrate by Parts.
Like this
gif.gif

Is this correct? If no then what could I do to this integral. I would be very thankful if someone would post an answer...
 
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Your attempt is valid, but you have created a more complex integral to solve. While there might be a way to solve this integral by dividing out to find the quotient, that too looks like it would create a messy integral to solve.
 
Break it down into ∫{\frac{x^3}{16xtanx+sinx}}dx+∫{\frac{56x^2sin^6x}{16xtanx+sinx}}dx
Then try long division. If you can't do long division with polynomials, I would recommend reading up on it. It creeps up quite a bit, and you're much better off knowing how to do it.

This is still going to be a nasty nasty integral, unless I'm missing something. I've not attempted it yet, but it seems like it might be easier that trying to to Integration by parts 20 times. Also With long division it may help to write ##{\tan{x}}## as ##{\frac{\sin{x}}{\cos{x}}}## and write the denominator as a fraction then simplify.
 

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