Results 1 to 8 of 8

Math Help - Find a real number for a continuous function

  1. #1
    Newbie
    Joined
    Feb 2014
    From
    New York
    Posts
    16

    Find a real number for a continuous function

    How would I go about doing this?

    Find a real number f so that: is a continuous function

    y = { 3x - 2d if x is less than or equal to zero
    {2x^2 + x + 5d^2 if x is greater than zero.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Nov 2013
    From
    California
    Posts
    2,363
    Thanks
    910

    Re: Find a real number for a continuous function

    Quote Originally Posted by IStandAlone99 View Post
    How would I go about doing this?

    Find a real number f so that: is a continuous function

    y = { 3x - 2d if x is less than or equal to zero
    {2x^2 + x + 5d^2 if x is greater than zero.
    do you mean a real number d?

    y is clearly continuous on either side of 0 so just pick d to ensure that the value at 0 agrees coming from both sides.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Feb 2014
    From
    New York
    Posts
    16

    Re: Find a real number for a continuous function

    Yeah I meant d....so if I put x=0....the equation would be: -2d = 5d^2?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Nov 2013
    From
    California
    Posts
    2,363
    Thanks
    910

    Re: Find a real number for a continuous function

    yep
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,617
    Thanks
    1581
    Awards
    1

    Re: Find a real number for a continuous function

    Quote Originally Posted by IStandAlone99 View Post
    How would I go about doing this?
    Find a real number f so that: is a continuous function
    y = { 3x - 2d if x is less than or equal to zero
    {2x^2 + x + 5d^2 if x is greater than zero.
    You want to solve $\displaystyle{\lim _{x \to {0^ - }}}3x - 2d = {\lim _{x \to {0^ + }}}2{x^2} + x + 5{d^2}$
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,583
    Thanks
    1418

    Re: Find a real number for a continuous function

    There are, of course, two correct answers to this.
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Newbie
    Joined
    Feb 2014
    From
    New York
    Posts
    16

    Re: Find a real number for a continuous function

    I'm feeling extremely stupid...how would I solve: -2c = 5c^2?
    Follow Math Help Forum on Facebook and Google+

  8. #8
    MHF Contributor
    Joined
    Nov 2013
    From
    California
    Posts
    2,363
    Thanks
    910

    Re: Find a real number for a continuous function

    $5c^2=-2c$
    $5c^2+2c=0$
    $c(5c+2)=0$

    I think you can you manage it from here
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 3
    Last Post: April 18th 2011, 08:19 AM
  2. Replies: 3
    Last Post: April 18th 2011, 07:24 AM
  3. find values such that f(x) is a real number
    Posted in the Calculus Forum
    Replies: 1
    Last Post: January 16th 2010, 05:09 AM
  4. The collection of continuous point of a real-valued function
    Posted in the Differential Geometry Forum
    Replies: 3
    Last Post: November 20th 2009, 12:04 AM
  5. Find all real-number solutions...
    Posted in the Algebra Forum
    Replies: 1
    Last Post: April 23rd 2008, 05:35 AM

Search Tags


/mathhelpforum @mathhelpforum