How do you find the integral intx^2/((x^2+2)^(3/2))dx ?

1 Answer
Aug 29, 2014

=1/2*x/sqrt(2+x^2)+c, where c is a constant

Explanation :

=intx^2/((x^2+2)^(3/2))dx

=intx^2/(x^3(1+2/x^2)^(3/2))dx

=int1/(x(1+2/x^2)^(3/2))dx

Using Integration by Substitution,

let's assume 2/x^2=t

then -4/xdx=dt

=int-dt/(4(1+t)^(3/2))

=-1/4int(1+t)^(-3/2)dt

=-1/4*((1+t)^(-1/2))/(-1/2)

=1/2*1/sqrt(1+t)+c, where c is a constant

Substituting t back,

=1/2*1/sqrt(1+2/x^2)+c, where c is a constant

=1/2*x/sqrt(2+x^2)+c, where c is a constant