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Integration: Evaluate the Definite Integral?

  • Thread starter KAISER91
  • Start date
  • #1
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Homework Statement



Q) Evaluate The Definite Integral:

∫ (x^3) / (1 + x^4) dx

Upper Limit: 1
Lower Limit: 0


Homework Equations





The Attempt at a Solution



I think I'm on the right track;


u = 1 + x^4
du/dx = 4x^3
du = 4x^3 dx
1/4 du = x^3 dx


When x = 0 ; u = 1
When x = 1 ; u = 2


Therefore;

∫ (1/4 du) / u

1/4 ∫ u^-1




I'm not sure if that last step is correct; but here is where I get stuck.

Help will be appreciated. Thanks.



BTW;

Answer given is (1/4) ln 2
 

Answers and Replies

  • #2
danago
Gold Member
1,122
4
[tex]
\int \frac{dx}{x} = ln(x) + C
[/tex]
 
  • #3
27
0
LMAOO!!!!

Silly me.

Nevermind, I got it now.
 

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