An integration involving inverse trig.

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SUMMARY

The integration problem presented involves calculating the definite integral \int_0^1 (2+\frac{1}{x+1}+\frac{2x+1}{x^2+4}) dx. The solution is definitively 2 + ln(\frac{5}{2}) + \frac{1}{2}arctan(\frac{1}{2}). The integration of the term \frac{2x+1}{x^2+4} can be simplified by splitting it into \frac{2x}{x^2+4} + \frac{1}{x^2+4}, where the first part requires a substitution and the second part utilizes the inverse tangent function. The formula \int \frac{dx}{x^2+a^2} = \frac{1}{a} arctan(\frac{x}{a}) + C is crucial for solving the integral involving the inverse tangent.

PREREQUISITES
  • Understanding of definite integrals
  • Familiarity with logarithmic functions
  • Knowledge of inverse trigonometric functions, specifically arctan
  • Basic skills in substitution methods for integration
NEXT STEPS
  • Study integration techniques involving substitution in calculus
  • Learn about the properties and applications of inverse trigonometric functions
  • Explore the derivation and applications of the formula \int \frac{dx}{x^2+a^2}
  • Practice solving similar definite integrals with mixed functions
USEFUL FOR

Students studying calculus, particularly those focusing on integration techniques, as well as educators seeking to enhance their teaching methods in advanced mathematics.

Charismaztex
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Homework Statement



The question is integrate

\int_0^1 (2+\frac{1}{x+1}+\frac{2x+1}{x^2+4}) dx

Homework Equations



\int_0^1 (2+\frac{1}{x+1}+\frac{2x+1}{x^2+4}) dx =2 + ln(\frac{5}{2}) +\frac{1}{2}arctan(\frac{1}{2}) (yes, it's a prove question)

The Attempt at a Solution



The first two parts I have no problem but I am not quite sure how to integrate the

\frac{2x+1}{x^2+4} part. I know it has to do with arctan but I'm not quite sure about the 2x+1 part.

Thanks in advance,
Charismaztex
 
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Split up the last fraction so that you have \frac{2x}{x^{2}+4} + \frac{1}{x^{2}+4}. Use a simple substitution for the first fraction and then the second fraction will involve the inverse tangent. In general,

\int \frac{dx}{x^2+a^2} = \frac{1}{a} arctan(\frac{x}{a}) + C
 
ahh! I completely missed that step! Thanks for your help :)

Charismaztex
 

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