• 2022-10-26
    8.下列函数在$x_0=0$处连续的为()。
    A: $f(x) = \left\{ {\begin{array}{*{20}{c}}
    {{{\rm{e}}^{ - \frac{1}{{{x^2}}}}},\;\;x \ne 0} \\
    {0,\;\;\;\;\;x = 0} \\
    \end{array}} \right.
    $
    B: $f(x) = [x]
    $
    C: $f(x) = {\mathop{\rm sgn}} (\sin x)
    $
    D: $f(x) = \left\{ {\begin{array}{*{20}{c}}
    {\frac{{\sin x}}{{\left| x \right|}},\;\;x \ne 0} \\
    {1,\;\;\;\;\;\;\;x = 0} \\
    \end{array}} \right.
    $
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