Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Sine Question

  1. Nov 7, 2004 #1
    Hello.

    Please can someone help me with this :


    f(x)=sinx


    For the above, is y a function of x OR is y a function of Sine ?


    Secondly, I don't understand what it means by :

    a f(x)

    and f(ax)

    where a is 2.

    What I need to know is what does each do to the graph of sin x ?

    Also do each of the two af(x) and f(ax) pass the same points on the x axis as just sinx ?

    Please help me


    rog
     
  2. jcsd
  3. Nov 7, 2004 #2
    For f(x) = sin(x), f is a function of x.
    What is meant by af(x) is that the value of f(x) is multiplied by the constant a. The expression f(ax) means that x is multiplied by the constant a, and then function f is applied to that value.
    Hope that helps! :)
     
  4. Nov 7, 2004 #3

    Galileo

    User Avatar
    Science Advisor
    Homework Helper

    f(x)=sin(x) is also a function of sin(x).
    It depends how you look at it.
    If you take y=sin(x), then f(x)=y. So f is clearly a function of y=sin(x).
    However, since sin(x) is a function of x, f is also a function of x.

    If f were given by: f(x)=sin(x)+x, it would not be a function of sin(x), but only of x.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook