点x=2是函数y=x^2-1/x^2-3x+2的:(A)可去间断点 (B)跳跃间断点(C)无穷间断点
问题描述:
点x=2是函数y=x^2-1/x^2-3x+2的:(A)可去间断点 (B)跳跃间断点(C)无穷间断点
答
C
答
y=(x^2-1)/(x^2-3x+2)=[(x+1)(x-1)]/[(x-2)(x-1)]=(x+1)/(x-2)
选C
lim(x→2)(x+1)/(x-2)=3/0=∞