(2/3)(ln(x-1))-(2/3)ln(k+2)
=(2/3)[ln(x-1)-ln(k+2)]
=(2/3)ln[(x-1)/(k+2)]
当 k→∞ 时,(x-1)/(k+2)→0,ln[(x-1)/(k+2)]k→-∞,
(2/3)ln[(x-1)/(k+2)] →-∞
(2/3)(ln(x-1))-(2/3)ln(k+2) k --> ∞ 等于多少?怎么算的?
(2/3)(ln(x-1))-(2/3)ln(k+2)
=(2/3)[ln(x-1)-ln(k+2)]
=(2/3)ln[(x-1)/(k+2)]
当 k→∞ 时,(x-1)/(k+2)→0,ln[(x-1)/(k+2)]k→-∞,
(2/3)ln[(x-1)/(k+2)] →-∞