Hi
I am stuck on this problem integrating the following.
In order to integrate should I be integrating by parts and seperating the function into
Or should I be using the substitution method to do this?
I am very stuck - I know that but don't know if it's relevant to help me solve??
Thanks
u=1+x^2
du=arctan(x)
v=1+x^2
dv=arctan(x)
I=integral(u*dv) -->what you're looking for
I=uv-integral(v*du)=(1+x^2)^2-integral(v*du)
But integral(v*du)=integral(u*dv) they're the same integral
so,
I=(1+x^2)^2 -I
2*I=(1+x^2)^2
I=((1+x^2)^2)/2 --->this is the answer