[分析] 請教一題微分問題

[OSGrup (open將真的很可愛)]

            x^2   if x is irrational
Let f(x) = {
             0    if x is rational

Is f is differentiable at 0 ?

請指教,謝謝




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◆ From: 140.119.203.45
→ linch1:Yes!  f'(0)=0
推 Natsutaka:應該是的 導數值是0
→ linch1:利用定義及三明治定裡即可
推 ricky110777:有無理數稠密性