作业帮 > 数学 > 作业

求极限lim((1-x)^0.5-3)/(2+x^(1/3)) (x趋近于-8)

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/10/06 13:08:49
求极限lim((1-x)^0.5-3)/(2+x^(1/3)) (x趋近于-8)
分子分母同乘:[√(1-x) + 3 ] [(4+2*x^(1/3)+x^(2/3))] 有理化:
lim(x->-8) [√(1-x) -3 ] /(2+x^(1/3))
=lim(x->-8) [(1-x) - 9 ][(4+2*x^(1/3)+x^(2/3))] / {(8+x)*[√(1-x) + 3 ]}
=lim(x->-8) -[(4+2*x^(1/3)+x^(2/3))] / [√(1-x) + 3 ]
= -[4-4+4]/[3+3]
= -2/3