Results 1 to 2 of 2

Math Help - pre-Calculus HELP!

  1. #1
    tstaskal
    Guest

    Calculus HELP!

    Do not know what to do for the following:

    Find and simplify

    f(a+h) - f(a)

    for each function

    f(x) = 4 - x^2

    f(x) = x^2 +1
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,805
    Thanks
    696
    Hello, tstaskal!

    Do you understand functional notation at all?

    Given a function f(x)\!:\;f(a+h) means "replace each x with a+h."


    Do not know what to do for the following:

    Find and simplify f(a+h) - f(a) for each function:

    (1)\;f(x) \,= \,4 - x^2

    (2)\;f(x)\,=\, x^2 +1

    We are asked to find; . f(a+h) - f(a)

    Try to "read" what is says:
    . . (a) Find f(a+h) . . . replace x with a+h.
    . . (b) Then find f(a) . . . replace x with a.
    . . (c) Then subtract them: . f(a+h) - f(a)


    (1)\;f(x)\:=\:4 - x^2

    . . (a)\;f(a+h) \;= \; 4 - (a+h)^2\;=\;4 - (a^2 + 2ah + h^2) \;=  \;4 - a^2 - 2ah - h^2

    . . (b)\;f(a)\;=\;4 - a^2

    . . (c)\;f(a+h) - f(a)\;=\;(4 - a^2 - 2ah - h^2) - (4 - a^2) <br />
\;=  4 - a^2 - 2ah - h^2 - 4 + a^2

    Answer: . \boxed{-2ah - h^2}


    You see? . . . It's just basic Algebra . . .

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: December 13th 2011, 09:11 PM
  2. Replies: 2
    Last Post: June 25th 2010, 10:41 PM
  3. Replies: 1
    Last Post: February 11th 2010, 07:09 AM
  4. Calculus III But doesn't require Calculus :)
    Posted in the Calculus Forum
    Replies: 1
    Last Post: June 19th 2009, 04:23 PM
  5. Replies: 1
    Last Post: June 23rd 2008, 09:17 AM

Search Tags


/mathhelpforum @mathhelpforum