Lösung 2.2:4d
Aus Online Mathematik Brückenkurs 2
(Unterschied zwischen Versionen)
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- | {{ | + | The integral can be simplified by a so-called polynomial division. We add and take away |
- | < | + | <math>\text{1}</math> |
- | {{ | + | in the numerator and can thus eliminate the |
+ | <math>x^{2}</math> | ||
+ | -term from the numerator | ||
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+ | <math>\frac{x^{2}}{x^{2}+1}=\frac{x^{2}+1-1}{x^{2}+1}=\frac{x^{2}+1}{x^{2}+1}-\frac{1}{x^{2}+1}=1-\frac{1}{x^{2}+1}</math> | ||
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+ | Thus, we have | ||
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+ | <math>\int{\frac{x^{2}}{x^{2}+1}\,dx=\int{\left( 1-\frac{1}{x^{2}+1} \right)}}\,dx=x-\arctan x+C</math> |
Version vom 12:57, 21. Okt. 2008
The integral can be simplified by a so-called polynomial division. We add and take away \displaystyle \text{1} in the numerator and can thus eliminate the \displaystyle x^{2} -term from the numerator
\displaystyle \frac{x^{2}}{x^{2}+1}=\frac{x^{2}+1-1}{x^{2}+1}=\frac{x^{2}+1}{x^{2}+1}-\frac{1}{x^{2}+1}=1-\frac{1}{x^{2}+1}
Thus, we have
\displaystyle \int{\frac{x^{2}}{x^{2}+1}\,dx=\int{\left( 1-\frac{1}{x^{2}+1} \right)}}\,dx=x-\arctan x+C