→ k6416337 :1.不均勻，代入x_n=1/n會發現沒收斂到0 01/27 18:32
推 plover :f_n'(x)求一下,可以知道f_n(x)的圖.. 01/28 01:36
For nεＮ(n屬於自然數) , xε[0,1],
2nx
let f_n(x)=-----------
1+(nx)^2
Find the function f:[0,1]→Ｒ so that
f_n(x)→f(x) pointwisely on [0,1] as n→∞.
Prove or disprove that the convergence is uniform.
我覺得 f_n 應該是點狀收斂至 f(x)=0,
也認為 f_n 在 [0,1] 上uniformly convergent,但是 uniformly convergent
這部分,用定義證不太出來,麻煩板上大大幫忙 ^^~~
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Evaluate the double integral
5x^2+2xy+y^2
∫∫ e dA
E
E is the ellipse {(x,y)εＲ^2 | 5x^2+2xy+y^2 < 1} 感謝^^~~
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