Integrate 2y^2/y^2+4?

1 Answer
Jun 15, 2018

#int (2y^2)/(y^2+4)dy = 2y -4 arctan(y/2)+C#

Explanation:

Lower the degree of the numerator:

#(2y^2)/(y^2+4) = 2( (y^2+4-4)/(y^2+4)) = 2(1-4/(y^2+4))#

Now using the linearity of the integral:

#int (2y^2)/(y^2+4)dy = 2int dy -8 intdy/(y^2+4)#

#int (2y^2)/(y^2+4)dy = 2y -8int (2d(y/2))/(4((y/2)^2+1)#

#int (2y^2)/(y^2+4)dy = 2y -4 arctan(y/2)+C#