If $a = \sqrt {(21)} - \sqrt {(20)} $ and $b = \sqrt {(18)} - \sqrt {(17),}  $ then

  • A

    $a = b$

  • B

    $a + b = 0$

  • C

    $a > b$

  • D

    $a < b$

Similar Questions

If $x = {2^{1/3}} - {2^{ - 1/3}},$ then $2{x^3} + 6x = $

${{\sqrt {6 + 2\sqrt 3 + 2\sqrt 2 + 2\sqrt 6 } - 1} \over {\sqrt {5 + 2\sqrt 6 } }}$

$\root 4 \of {(17 + 12\sqrt 2 )} = $

${{{{[4 + \sqrt {(15)} ]}^{3/2}} + {{[4 - \sqrt {(15)} ]}^{3/2}}} \over {{{[6 + \sqrt {(35)} ]}^{3/2}} - {{[6 - \sqrt {(35)} ]}^{3/2}}}} = $

The value of $\sqrt {[12 - \sqrt {(68 + 48\sqrt 2 )} ]} = $