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    Right, Im retaking C3 after an epic fail of an exam result, and I am currently revising ( good ey?)
    Anyway, I cannot for the life of me remember how to find the range of a function. If someone could help, it would be very much appreciated.
    The question:
    y= \frac{-3x}{x-2} Find the range.

    Thank you.
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    Range is the y-values of the function.
    Try long division to help identify the asymptotes, sketch is helpful...
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    (Original post by ChappersBC)
    Right, Im retaking C3 after an epic fail of an exam result, and I am currently revising ( good ey?)
    Anyway, I cannot for the life of me remember how to find the range of a function. If someone could help, it would be very much appreciated.
    The question:
    y= \frac{-3x}{x-2} Find the range.

    Thank you.
    This is a transformed hiperbole
    the base function is y=\frac{1}{x}
    Find your function in following transformed form
    y=a\frac{1}{x-b}+c where a,b,c are real values
    THe range of it is all real value except b
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    As vc94 said, range is just all the values y can take, that is, everything you can get out of the functions. So here's a general set of things you could think about when doing this sort of question:

    - Is there anything that will make your graph shoot off to infinity? (division by zero, for example)

    - are there any values your function can't take? the usual culprits for this are 0 and negative numbers. (eg, 1/x can never equal zero, (x^2)+1 is always bigger than 1, etc).

    Spoiler:
    Show
    think of what happens when x=2. What happens when x gets bigger and bigger on the positive scale (i.e. x gets closer and closer to infinity) and when x gets bigger and bigger on the negative scale (i.e. gets closer and closer to minus infinity)?


    If you're still stuck, google an online graphing calculator and plot the thing (or D.I.Y.) - that'll help you see what sorts of things to be looking out for.

    I hope that helps
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    domain is x not equal to 2 so range should be easy to find. sketch it.
 
 
 
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