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Homework Help: Some questions about my assignment of functions

  1. Oct 20, 2006 #1
    Hi, I've been sick over the last week (strep throat) and I just found out today that I have to hand in an assignment by 2pm. Ive completed all the problems but 4 which I dont know how to do. If someone could do them or help me do them asap i'd be forever grateful.
    1)Is the following graph symmetric with respect to:
    a)the x-axis b)the y-axis c)the origin
    y=(x^2 - 4)/(2x^2)

    2)Find the domain of
    a)7Sqrt(x^3-1) ... it's the little 7 ontop of the sqrt, not 7 * sqrt
    b)(2)/(x^2 + 6x + 9)

    3)find the average rate of change of the f(x)= x^3 from 1 to 2x

    4)if y=|x| then draw the following graph
    b)y=|x| +4
    c)y=|x+2| + 4
    I realise that you won't be able to graph it in form of text so this is my e-mail european_footballstar@hotmail.com
    Please show your work*
    If anyone at all could help me I would really appreciate it and you'd be saving my life!! Desperate please help !
  2. jcsd
  3. Oct 20, 2006 #2


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    First thing you are going to have to do is show a little effort on your part. What is the DEFINITION of "symmetric with respect to " the x-axis, the y-axis, the origin?

    Then it's not a squareroot at all- it is a 7th root.
    Unless otherwise given, the domain is the set of all x for which the caculation can be done. For each of these is there any x for which it CAN'T be done?

    You mean from 1 to 2. How much is f(2) different from f(1)? How much does it change "per x"?

    Again, what you have said makes no sense. If y= |x| then it can't be any of those other things. I suspect you mean that you are given the graph of y= |x| and are supposed to use it to graph these other functions. Hint: each of these changes shifts the graph left-right or up-down. Which is which?
    Tricking your teacher into thinking you know how to do these when you don't is not saving your life- it's just making things harder for you later. By the way, it's a very bad practice to give your e-mail address out profigately. I won't e-mail you because I don't want you to have my e-mail address.
  4. Oct 20, 2006 #3


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    Science Advisor

    I've merged the two threads into one.

    andreipanait, you were supposed to have read the forum rules before posting:

    Do NOT post homework in the MATH threads.

    Do NOT post the same thing more than once.

    For homework help-TRY and show us what you have done.
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