Results 1 to 4 of 4

Math Help - a little rusty...help me get started

  1. #1
    Newbie
    Joined
    Apr 2013
    From
    Canada
    Posts
    2

    a little rusty...help me get started

    hey everyone!! so i'm brand new to this forum and am taking a pre-calculus class and am just going through a book on my own time before starting the class. I'm familiar with lots of these things but as my title says, i'm a little rusty. so i just had a couple simple questions here regarding a couple functions.

    AND PLEASE SPELL OUT THE ANSWERS STEP-BY-STEP WITH MAYBE SOME EXPLANATION, my book just gives me the answer without any steps

    #1)

    Given f(x)= x^2 - 2x +3

    Find f(x+1)
    ****The answer in the book I'm using is x^2 +2**** and i can't quite seem to see why


    #2 (and perhaps related to why I can't quite get the first question)

    Given w = z(m) = 3m^2 -10

    Find z(x-1)
    ****The annswer in the book i'm using is 3x^2-6x-7

    Thanks!!!!!!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member
    Joined
    Nov 2012
    From
    Mexico
    Posts
    53
    Thanks
    7

    Re: a little rusty...help me get started

    Initially, the function depends on the variable 'x'; then the variable is 'x+1', so you just have to substitute that variable in the equation, for example:

    If f(x)= x^2 - 2x +3, then f(x+1)= (x+1)^2 - 2(x+1) +3 = x^2+2x+1-2x-2+3 = x^2+2
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    10,212
    Thanks
    419
    Awards
    1

    Re: a little rusty...help me get started

    Quote Originally Posted by cookiesareverytasty View Post
    #2 (and perhaps related to why I can't quite get the first question)

    Given w = z(m) = 3m^2 -10

    Find z(x-1)
    ****The annswer in the book i'm using is 3x^2-6x-7

    Thanks!!!!!!
    Give #2 a try, based on the previous post and let us know how far you have gotten.

    -Dan
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Apr 2013
    From
    Canada
    Posts
    2

    Re: a little rusty...help me get started

    yea i got both of them now, thx guys!

    the dependent variable was set up the same so i was making the same basic mistake each time. got it now thx! i'm sure i'll be posting more and more lol
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: December 4th 2012, 05:44 AM
  2. PDE trouble - I'm a little rusty
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: August 8th 2010, 07:51 AM
  3. Rusty on my math
    Posted in the Algebra Forum
    Replies: 5
    Last Post: August 27th 2009, 08:43 PM
  4. Bit rusty on my log rearranging
    Posted in the Algebra Forum
    Replies: 3
    Last Post: June 12th 2009, 08:43 AM
  5. Replies: 1
    Last Post: February 26th 2009, 11:51 AM

Search Tags


/mathhelpforum @mathhelpforum