The rational functions which we shall consider
here for integration purposes will be those whose denominators can be factorised into
linear and quadratic factors Assume that we want to evaluate 
P( )
Q( )
∫xx dx
, where P( )
Q( )
x
x
is proper rational function It is always possible to write the integrand as a sum of
simpler rational functions by a method called partial fraction decomposition After this,
the integration can be carried out easily using the already known methods