What is int (-2x^3-x^2+x+2 ) / (3x^2+2x +3 )?

1 Answer
Dec 17, 2017

(25Ln(3x^2+2x+3)+10sqrt2arctan((3x+1)/(2sqrt2))-18x^2+6x)/54+C or

=25/54Ln(3x^2+2x+3)+(5sqrt2)/27arctan((3x+1)/(2sqrt2))-(3x^2-x)/9+C

Explanation:

int (-2x^3-x^2+x+2)/(3x^2+2x+3)*dx

=-1/9int (18x^3+9x^2-9x-18)/(3x^2+2x+3)*dx

=-1/9int ((6x-1)*(3x^2+2x+3)-(25x+15))/(3x^2+2x+3)*dx

=-1/9int (6x-1)dx+1/9int (25x+15)/(3x^2+2x+3)*dx

=-1/9*(3x^2-x)+C+1/9int (25/6*(6x+2)+20/3)/(3x^2+2x+3)*dx

=-1/9*(3x^2-x)+C+25/54int (6x+2)/(3x^2+2x+3)*dx+20/27int (dx)/(3x^2+2x+3)

=-1/9*(3x^2-x)+25/54ln(3x^2+2x+3)+C+20/27int (3dx)/(9x^2+6x+9)

=-1/9*(3x^2-x)+25/54ln(3x^2+2x+3)+C+20/27int (3dx)/((3x+1)^2+(2sqrt2)^2)

=-1/9*(3x^2-x)+25/54ln(3x^2+2x+3)+(5sqrt2)/27arctan((3x+1)/(2sqrt2))+C

=(25Ln(3x^2+2x+3)+10sqrt2arctan((3x+1)/(2sqrt2))-18x^2+6x)/54+C