求第四题详细解答步骤 谢谢?

2025-05-10 19:35:50
推荐回答(1个)
回答1:

f(x) = x|x-5|/[(x-1)(x-5)sinx ]

lim(x->0) x|x-5|/[(x-1)(x-5)sinx ]

=lim(x->0) |x-5|/[(x-1)(x-5) ]

=1

x=0 : 可去间断点 (第1类间断点)

lim(x->5+) x|x-5|/[(x-1)(x-5)sinx ]

=lim(x->5+) x/[(x-1)sinx ]

= 5/(4sin1)

lim(x->5-) x|x-5|/[(x-1)(x-5)sinx ]

=lim(x->5-) -x/[(x-1)sinx ]

= -5/(4sin1)

x=5: 跳跃间断点 (第1类间断点)

ans : C