If $p,q,r$ are in $G.P$ and ${\tan ^{ - 1}}p$, ${\tan ^{ - 1}}q,{\tan ^{ - 1}}r$ are in $A.P.$ then $p, q, r$ are satisfies the relation
$p = q = r$
$p \ne q \ne r$
$p + q = r$
None of these
The number of different possible values for the sum $x+y+z$, where $x, y, z$ are real number such that $x^4+4 y^4+16 z^4+64=32 x y z$ is
Let $f: R \rightarrow R$ be such that for all $\mathrm{x} \in \mathrm{R}\left(2^{1+\mathrm{x}}+2^{1-\mathrm{x}}\right), f(\mathrm{x})$ and $\left(3 ^\mathrm{x}+3^{-\mathrm{x}}\right)$ are in $A.P.$, then the minimum value of $f(x)$ is
If arithmetic mean of two positive numbers is $A$, their geometric mean is $G$ and harmonic mean is $H$, then $H$ is equal to
If the ratio of $H.M.$ and $G.M.$ of two quantities is $12:13$, then the ratio of the numbers is
Let the range of the function
$f(x)=\frac{1}{2+\sin 3 x+\cos 3 x}, x \in \operatorname{IR} \text { be }[a, b] .$ If $\alpha$ and $\beta$ are respectively the $A.M.$ and the $G.M.$ of a and $b$, then $\frac{\alpha}{\beta}$ is equal to :