Results 1 to 2 of 2

Math Help - limits

  1. #1
    Junior Member
    Joined
    Sep 2008
    Posts
    71

    limits

    Suppose that neither lim x->a f(x) nor limit g(x) exists. Find functions f and g so that the following limits exist or explain why it is impossible to do so.

    (a) lim x->a (f(x)+f(x))

    (b)lim x->a (f(x) * g(x))

    where do I evaluate from?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Banned
    Joined
    Oct 2009
    Posts
    4,261
    Thanks
    2
    Quote Originally Posted by asweet1 View Post
    Suppose that neither lim x->a f(x) nor limit g(x) exists. Find functions f and g so that the following limits exist or explain why it is impossible to do so.

    (a) lim x->a (f(x)+f(x))


    \color{red}\mbox{I suppose you meant to write here }\lim_{x\rightarrow a}\left(f(x)+g(x)\right)\,,\,\,\mbox{so you can take } \color{red}f(x)=\frac{1}{x}\,\mbox{ and }\,\,g(x)=-\frac{1}{x}\,,\,\,a=0


    (b)lim x->a (f(x) * g(x))


    \color{red}\mbox{Take }f(x)=\left\{\begin{array}{cc}0&\mbox{ if }\,x\leq 0\\1&\mbox{ if } x>0\end{array}\right. \,\mbox{ and }\,\,g(x)=\left\{\begin{array}{cc}1&\mbox{ if }\,x\leq 0\\0&\mbox{ if } x>0\end{array}\right.


    \color{blue}Tonio

    where do I evaluate from?
    .
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Using limits to find other limits
    Posted in the Calculus Forum
    Replies: 7
    Last Post: September 18th 2009, 05:34 PM
  2. Function limits and sequence limits
    Posted in the Differential Geometry Forum
    Replies: 0
    Last Post: April 26th 2009, 01:45 PM
  3. HELP on LIMITS
    Posted in the Calculus Forum
    Replies: 4
    Last Post: September 23rd 2008, 11:17 PM
  4. Limits
    Posted in the Calculus Forum
    Replies: 5
    Last Post: September 21st 2008, 10:52 PM
  5. [SOLVED] [SOLVED] Limits. LIMITS!
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 25th 2008, 10:41 PM

Search Tags


/mathhelpforum @mathhelpforum