In a triangle ABC , the sides $\mathrm{a}, \mathrm{b}, \mathrm{c}$ are such that they are the roots of the equation $x^3-11 x^2+38 x-40=0$ Then

$$ \frac{\cos A}{a}+\frac{\cos B}{b}+\frac{\cos C}{c}= $$

In a triangle ABC with usual notations if $\mathrm{a}=13$, $b=14, c=15$ Then $\sin A=$

$$ \int_0^3 \frac{d x}{(x+2) \sqrt{x+1}}= $$

If $2 \tan ^{-1}(\cos x)=\tan ^{-1}(2 \operatorname{cosec} x)$, then the value of $x$ is