lim(x趋近于0)[sin6x+xf(x)]/x^3=0,则lim(x趋近于0)[6+f(x)]/x^2=?rt

问题描述:

lim(x趋近于0)[sin6x+xf(x)]/x^3=0,则lim(x趋近于0)[6+f(x)]/x^2=?
rt

,lim(x趋近于0)[sin6x+xf(x)]/x^3=0,则知道f(x) 是低天X^2的。所以(6+F(X))是低于X^2的。从而 lim(x趋近于0)[6+f(x)]/x^2=0.

lim(x趋近于0)[6+f(x)]/x^2=lim(x趋近于0)6/x^2+lim(x趋近于0)f(x)/x^2=lim(x趋近于0)sin6x/x^3+lim(x趋近于0)xf(x)/x^3=lim(x趋近于0)[sin6x+xf(x)]/x^3=0.