$\frac{1}{2+\tan x}+C$

$-\frac{1}{2 \tan x+1}+C$

$\frac{\cos x}{\cos x+2 \sin x}+C$

$-\frac{\cos x}{2 \cos x+\sin x}+C$

0

1

3

2

$-e^{-x}\left(x^3-x^2+5 x-1\right)+C$

$e^{-x}\left(x^3-x^2+5 x-1\right)+C$

$e^{-x}\left(x^3+x^2+5 x+1\right)+C$

$-e^{-x}\left(x^3+x^2+5 x+1\right)+C$

$x \sec x+C$

$x \tan ^2 x+C$

$x \sec ^2 x+C$

$x \tan x+C$