If $\theta$ denotes the acute angle between the curves $y=10-x^2$ and $y=2+x^2$, at a point of the intersection, then $|\tan \theta|$ is equal to

If $y=a \log x+b x^2+x$ has its extremum values at $x=-1$ and $x=2$, then

The set of all points, for which $f(x)=x^2 e^{-x}$ strictly increases, is

The abscissa of the point on the curve $y=\mathrm{a}\left(\mathrm{e}^{\frac{x}{a}}+\mathrm{e}^{-\frac{x}{a}}\right)$ where the tangent is parallel to the X -axis is