※ 引述《zxc45693 ()》之銘言：
: 求解14,15題，感恩
: https://i.imgur.com/XSiXPvn.jpg
14.
|x - 2| < 1 => |x| < 3
|x^2 - 4| = |x - 2||x + 2| < |x - 2|[|x| + 2] < |x - 2|5
取δ = min(1, ε/5)
=> |x^2 - 4| = |x - 2||x + 2| < (ε/5) (3 + 2) = ε
15.
f(x) = √x
|√x - 2| = |x - 4|/|√x + 2|
< δ/2 <= ε
任選滿足0 < δ <= 2ε的δ均可
例如0.2
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