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Integration by parts

  • #1

Homework Statement


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upload_2016-6-2_21-5-50.png


Homework Equations


∫ f(x) g'(x) dx = f(x) g(x) - ∫ f '(x) g(x) dx

f(x)=√(1+x^2)
f '(x)=x * 1/√(1+x^2)

g'(x)=1
g(x)=x

The Attempt at a Solution


∫ √(1+x^2) * 1 dx
=x * √(1+x^2) - ∫ x^2 * 1/√(1+x^2) dx

Further integration just makes the result look further from what it's supposed to look like
 

Answers and Replies

  • #2
240
42
=x * √(1+x^2) - ∫ x^2 * 1/√(1+x^2) dx
The latter part may help to go to your answer. You maybe can try to make it become ##\frac{x^2}{\sqrt{1+x^2}}=\sqrt{1+x^2}-\frac{1}{\sqrt{1+x^2}}.##
 
  • #3
The latter part may help to go to your answer. You maybe can try to make it become ##\frac{x^2}{\sqrt{1+x^2}}=\sqrt{1+x^2}-\frac{1}{\sqrt{1+x^2}}.##
Thank you!
 

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