If $x + \sqrt {({x^2} + 1)} = a,$ then $x =$
${1 \over 2}(a + 1/a)$
${1 \over 2}(a - 1/a)$
$(a + {a^{ - 1}})$
None of these
Let ${7 \over {{2^{1/2}} + {2^{1/4}} + 1}}$$ = A + B{.2^{1/4}} + C{.2^{1/2}} + D{.2^{3/4}}$, then $A+B+C+D= . . .$
The value of $\sqrt {[12 - \sqrt {(68 + 48\sqrt 2 )} ]} = $
The value of the fifth root of $10^{10^{10}}$ is
If ${{{{({2^{n + 1}})}^m}({2^{2n}}){2^n}} \over {{{({2^{m + 1}})}^n}{2^{2m}}}} = 1,$ then $m =$
The value of ${{15} \over {\sqrt {10} + \sqrt {20} + \sqrt {40} - \sqrt 5 - \sqrt {80} }}$ is