※ 引述《bitchdog (PEaCE)》之銘言：
: lim √￣￣￣￣￣￣
: x→∞ x ^ 2 + x - x
lim √(x^2 + x) - x
x→∞
(√(x^2 + x) - x)(√(x^2 + x) + x)
= lim ------------------------------------
x→∞ √(x^2 + x) + x
x^2 + x - x^2
= lim -----------------
x→∞ √(x^2 + x) + x
x
= lim -----------------
x→∞ √(x^2 + x) + x
x
= lim ------------------------
x→∞ (x)(√(1 + (1/x)) + 1)
1 1 1
= lim ------------------- = ------- = ---
x→∞ √(1 + (1/x)) + 1 1 + 1 2
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.119.27.68