Calculating the Integral of a Rational Function

electronic engineer
Messages
145
Reaction score
3
how to calculate the calculus of this rational function:

\int \frac{dx}{{x+x^6}}

could anyone get me through the solution?!
 
Last edited:
Physics news on Phys.org
Hint:

\frac{1}{{x + x^6 }} = \frac{1}{{x\left( {1 + x^5 } \right)}} = \frac{{\frac{1}{{x^6 }}}}{{\frac{{1 + x^5 }}{{x^5 }}}} = \frac{{\frac{1}{{x^6 }}}}{{\frac{1}{{x^5 }} + 1}}
 
so final result:

-0.2* ln(1+x^-5)


is that right?
 
Last edited:
electronic engineer said:
so final result:

-0.2* ln(1+x^-5)


is that right?
Indeed, if you don't forget the constant of integration :wink:
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top