working out is, complete the square on the bottom as:
(x^{2}+2x+1)cos^{2}x-2(1+x)sinxcosx +sin^{2}x -cos^{2}x-sin^{2}x= \\ \\ ((x+1)cosx-sinx)^{2}-1
and we note that
\frac{d}{dx} (x+1)cosx-sinx= -(1+x)sinx
so the integral is in the form
\int \frac{f'(x)}{f^{2}(x)-1}dx...