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◆ From: 122.116.6.196
※ 編輯: u2150260 來自: 122.116.6.196 (07/10 22:44)
∞
1. Let Bn be a countable set ,n=1,2......Show that ∪Bn is countable
n=1
2.find the inverse function of the function f(x)= e^x/x - 2e^(-x)
3.Let f(x,y)=cos^2x /2 +y^2 -ycosx -y/2 +1 Find (x0,y0) such that
f(x0,y0)≦f(x,y) for all x and y and the value of f(x0,y0)
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