Find the derivative of $\ln\left(1+x\right)$

$\frac{d}{dx}\left(\ln\left(\mathrm{sech}\left(3x+8\right)\right)\right)$

$\frac{d}{dx}\ln\left(x^2+1\right)$

$\frac{d}{dx}\left(\ln\left(1+x\right)\right)$

$\frac{d}{dx}\left(\sqrt{\frac{x\left(x+2\right)}{\left(2x+1\right)\left(5x+3\right)}}\right)$

Find the derivative

$\frac{d}{dx}\left(x^2+y^2\right)$

$\frac{d}{dx}\left(\arctan\left(x-\sqrt{1+x^2}\right)\right)$

$\frac{d}{dx}\arctan\left(x-\sqrt{1+x^2}\right)$