lim[(x^5+x^4)^(1/5)-(x^5-x^4)^(1/5)].x趋近于正无穷大,
问题描述:
lim[(x^5+x^4)^(1/5)-(x^5-x^4)^(1/5)].x趋近于正无穷大,
答
∵由泰勒公式展开,得(符号o(x)表示高阶无穷小) (1+1/x)^(1/5)=1+(1/5)/x-(2/25)/x²+o(1/x²) (1-1/x)^(1/5)=1-(1/5)/x-(2/25)/x²+o(1/x²)∴(1+1/x)^(1/5)-(1-1/x)...