Re: [考古] 東吳92商數
※ 引述《frde (蒙其D魯夫)》之銘言：
: x f(t)
: 3. 6 + ∫ ______ dt = 2X^1/2
: a t^2
: 求 a = ?
: 6.
: Use Lagrange multipliers to maximize f(x,y,z)=x+y+z subject to
: 1 1 1
: -- + -- + -- = 1
: x y z
3. 兩邊對 x 微分
f(x) 1 3
------ = ----- => f(x) = x^(---) 代回原方程式
x^2 √x 2
x t^(3/2)
6 + ∫ --------- dt = (2)(x^(1/2))
a t^2
x
∫ t^(-1/2) dt = (2)(x^(1/2)) - 6
a
|x
(2)(t^(1/2)) | = (2)(x^(1/2)) - 6
|a
(2)(x^(1/2)) - (2)(a^(1/2)) = (2)(x^(1/2)) - 6
a^(1/2) = 3 => a = 3^2 = 9
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07/08 19:27, , 1F
07/08 19:27, 1F
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