Consider the given integral.
∫cos2x+x+1x2+sin2x+2xdx
t=x2+sin2x+2x
Differentiate w.r.t x, we get.
dtdx=2x+2cos2x+2
dt2x+2cos2x+2=dx
dt2(x+cos2x+1)=dx
Integrate w.r.t t, we get
=12∫(cos2x+x+1x)t×dt(x+cos2x+1)
1=12∫1tdt
=12lnt+c
=12ln(x+cos2x+1)+c
Hence, this is the answer.