$\mathrm {\dfrac{d}{d x}\left(\cos \dfrac{1}{x}\right)}$ এর মান কোনটি ?

$\mathrm {-\dfrac{1}{x^{2}}~ \cos \dfrac{1}{x}}$

$\mathrm {-\dfrac{1}{x^{2}} ~\sin\dfrac{1}{x}}$

$\mathrm {\dfrac{1}{x^{2}}~ \sin\dfrac{1}{x}}$

$\mathrm {\dfrac{1}{x^{2}}~ \cos \dfrac{1}{x}}$