高数题如图?
ans: D
f(x) =ln|x|/ { (x^2-x).[1+2^(1/(x-2))]}
lim(x->1) f(x)
=lim(x->1) ln|x|/ { (x^2-x).[1+2^(1/(x-2))]}
=lim(x->1) ln(1+(x-1) )/ { (x^2-x).[1+2^(1/(x-2))]}
=lim(x->1) 1/ { x.[1+2^(1/(x-2))]}
=1/(1+1/2)
=2/3
x=1, 可去间断点
lim(x->0+) f(x)
=lim(x->0+) ln|x|/ { (x^2-x).[1+2^(1/(x-2))]}
=(-2/3 ) .lim(x->0+) ln|x|/ x
->+无穷
x=0, 无穷间断点
lim(x->2+) f(x)
=lim(x->2+) ln|x|/ { (x^2-x).[1+2^(1/(x-2))]}
=(1/2)ln2. lim(x->2+) 1/ [1+2^(1/(x-2))]
=0
lim(x->2-) f(x)
=lim(x->2-) ln|x|/ { (x^2-x).[1+2^(1/(x-2))]}
=(1/2)ln2. lim(x->2-) 1/ [1+2^(1/(x-2))]
=(1/2)ln2. [ 1/ (1+0)]
=(1/2)ln2
x=2, 跳跃间断点