Tính a) căn 121 b) - căn ((-8)^2) c) (- căn 2)^2 d) - (căn 1/4)^2

a) \[\sqrt {121} = \sqrt {{{11}^2}} = 11\]

b) \[ - \sqrt {{{\left( { - 8} \right)}^2}} = - \sqrt {{8^2}} = - 8\]

c) \[{\left( { - \sqrt 2 } \right)^2} = {\left( { - 1} \right)^2}.{\left( {\sqrt 2 } \right)^2} = 1.2 = 2\]

d) \[ - {\left( {\sqrt {\frac{1}{4}} } \right)^2} = - \frac{1}{4}\]