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来自Android客户端1楼2014-09-06 16:45回复
    Take the limit:
    lim_(x->0) (1-sin(x))^(2/x)
    Indeterminate form of type 1^infinity. Transform using lim_(x->0) (1-sin(x))^(2/x) = e^(lim_(x->0) (2 log(1-sin(x)))/x):
    = e^(lim_(x->0) (2 log(1-sin(x)))/x)
    Factor out constants:
    = e^(2 (lim_(x->0) (log(1-sin(x)))/x))
    Indeterminate form of type 0/0. Applying L'Hospital's rule we have, lim_(x->0) (log(1-sin(x)))/x = lim_(x->0) (( dlog(1-sin(x)))/( dx))/(( dx)/( dx)):
    = e^(2 (lim_(x->0) (cos(x))/(-1+sin(x))))
    The limit of a quotient is the quotient of the limits:
    = exp((2 (lim_(x->0) cos(x)))/(lim_(x->0) (-1+sin(x))))
    The limit of cos(x) as x approaches 0 is 1:
    = e^(2/(lim_(x->0) (-1+sin(x))))
    The limit of a constant is the constant:
    The limit of a sum is the sum of the limits:
    = e^(2/(-1+lim_(x->0) sin(x)))
    The limit of sin(x) as x approaches 0 is 0:
    Answer: |
    | = 1/e^2


    来自Android客户端3楼2014-09-06 16:59
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      第二个重要极限


      IP属地:江苏4楼2014-09-06 17:00
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        我的第一反应是两边取ln


        IP属地:广东来自Android客户端5楼2014-09-06 17:37
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