Results 1 to 2 of 2

Thread: A function, find "a" and "b" ?

  1. #1
    Junior Member
    Nov 2009

    A function, find "a" and "b" ?

    Consider the function: f(x) = (x+a)/(bx+2)

    The curve crosses the point P (0,1/2)

    And the line (y=1) is an asymptote.

    Find a and b... Help is very much appreciated !!! thank you!!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Jan 2010
    You might not know this, but:

    If the degree of the numerator (x+a) and the deniminator (bx+2) are equal, then the asymptote is equal to the ratio of the leading coefficients of the two.

    Ask yourself: What is the asymptote's level? It is y=1. Now ask, what are the leading coefficients of x+a and bx+2? How can you express 1 as a ratio of the two coefficients?

    This should answer your need to find b.

    Now ask yourself: What can I use the other information ( (0,f(0)) = (0,1/2) ) for? Well, you can find a. Try inserting 0 in your function. What do you get? How can you find a from this new information, and the fact that f(0)=1/2?

    You should be done by now

    Happy mathing
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 3
    Last Post: Oct 17th 2011, 03:50 PM
  2. Replies: 2
    Last Post: Jun 4th 2011, 01:11 PM
  3. Replies: 2
    Last Post: Apr 24th 2011, 08:01 AM
  4. Replies: 1
    Last Post: Oct 25th 2010, 05:45 AM
  5. Replies: 1
    Last Post: Jun 4th 2010, 11:26 PM

Search Tags

/mathhelpforum @mathhelpforum