f(x)一阶导数在x趋向于无穷时极限为2,那x趋向于无穷时f(x+k)-f(x)等于

问题描述:

f(x)一阶导数在x趋向于无穷时极限为2,那x趋向于无穷时f(x+k)-f(x)等于