$\frac{d}{d x}\left(a^{20}\right)$ এর মান কোনটি?

If $f(x) = \frac{{{e ^{4x}}}}{{1 + 2{e ^x}}} than\,\,f'\left( 0 \right)\,\,is-$

If $y=e^{\sin^{2}x +\sin^{4}x + \sin ^{6}x +....+\infty}$ , then $\dfrac {dy}{dx} =?$

If $y=\tan^{-1}\left(\dfrac {\log_{e}(e/x^{2})}{\log_{e}(ex^{2})}\right)+\tan^{-1}\left(\dfrac{3+2\log_{e}x}{1-6\log_{e}x}\right)$ then $\dfrac{d^{2}y}{dx^{2}}$ is-