If ${x^y} = {y^x},$then ${(x/y)^{(x/y)}} = {x^{(x/y) - k}},$ where $k = $
$0$
$1$
$-1$
None of these
If $x + \sqrt {({x^2} + 1)} = a,$ then $x =$
The rationalising factor of $2\sqrt 3 - \sqrt 7 $ is
The square root of $\frac{(0.75)^3}{1-(0.75)}+\left[0.75+(0.75)^2+1\right]$ is
The equation $\sqrt {(x + 1)} - \sqrt {(x - 1)} = \sqrt {(4x - 1)} $, $x \in R$ has
${4 \over {1 + \sqrt 2 - \sqrt 3 }} = $