$\log \left(\frac{x^2+2}{\sqrt{x^2+1}}\right)+C$

$\log \left(x^2+2\right)-2 \log \left(x^2+1\right)+C$

$\log \left(\frac{\left(x^2+2\right) x}{\sqrt{x^2+1}}\right)+C$

$\log \left(\frac{x^2+1}{\sqrt{x^2+2}}\right)+C$

$\frac{\sqrt{7}}{3}$

$3 \sqrt{7}$

$\frac{3}{\sqrt{7}}$

$\frac{3}{7}$

$\frac{1}{25}[17 \log |4 \cos x-3 \sin x|-6 x]+C$

$\frac{1}{25}[x-18 \log |4 \cos x-3 \sin x|]+C$

$\frac{1}{25}[\log |4 \cos x-3 \sin x|-18 x]+C$

$\frac{1}{25}[17 x-6 \log |4 \cos x-3 \sin x|]+C$

$\frac{e^{4 x}}{25}(7 \sin 3 x-\cos 3 x)+C$

$\frac{e^{4 x}}{25}(\sin 3 x-7 \cos 3 x)+C$

$\frac{e^{4 x}}{5}(7 \sin 3 x+\cos 3 x)+C$

$\frac{e^{4 x}}{5}(\sin 3 x+7 \cos 3 x)+C$