作者stillboy (joey)
看板trans_math
标题Re: [连续] 一些问题
时间Sat Nov 24 09:56:55 2007
※ 引述《wing10588 (tsubasa)》之铭言:
: 是非题 :
: a. If the function h(x)=f(x)+g(x) is continuous at the point c
: ,then f(x) and g(x) are also continuous at c.
错:不一定,若h(x)=f(x)+g(x)连续 不代表 f(x)+g(x)连续.例子可自己找
: b. If the function f(x) and g(x) are differentiable at the point c then
: the function h(x)=f(x)+g(x) is differentiable at c.
对:这是定理
: c. Let f(x) and g(x) are functions on R ,then lim f(x)+lim g(x)=lim(f+g)(x)
: x->c x->c x->c
其实题目有点不董,因为他说funtions on R 是说 此极限值等於R?
若是等於R,後者必成立,因为这是定理,而且还要会证
: d. If f(x) is a function on the closed internal [a,b] with f(a)<f(b),then
: for all L:f(a)<L<f(b)there exists c: a<=c <=b such that f(c)=L
对:这是中间值定理
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◆ From: 124.8.224.72
1F:推 wing10588:谢谢~~~^^~~ 163.27.101.65 11/24 10:14
2F:推 stillboy:hi~之前没看清楚,这是一个题组? 124.8.239.185 11/25 21:32
3F:→ stillboy:第四题有盲点,因为他没说f是连续 124.8.239.185 11/25 21:32
4F:→ stillboy:所以第四题也是错的 124.8.239.185 11/25 21:33
5F:推 wing10588:是一组题的~ 140.130.189.36 11/28 15:01