作者dreamingaway (Wherever I May Roam)
看板Math
标题[微积] 两题微积分
时间Thu Dec 30 18:57:24 2010
1. Define a function f:R→R by f(x)=0 if x belongs to R\Q,
and f(x)=1/p if x=q/p where p,q belong to Z, p≧1 and gcd{p,q}=1.
Show that lim f(x)=0
x→1/2
2. Let f,g:[0,1]→R, be continuous functions. Define h(x)=max{f(x),g(x)}
for all x belong to [0,1]. Show that h(x) is also a continuous function.
请问这2题要怎麽做 谢谢
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1F：推 GaussQQ :第一题可用定义 12/30 20:21
2F：→ GaussQQ :第二题用h(x)=1/2{f(x)+g(x)+|f(x)-g(x)|} 12/30 20:22