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    Hi guys,

    I'm revising for the AQA Core 2 exam and came across one I don't understand - I'm not very good at transformations of functions so it might be obvious to you guys.

    If you had a graph and you applied the transformation f(x/2) does this just divide each x value by 2 effectively squishing the graph towards the y axis?
    Also, if you applied the transformation f(4-x) does this just mean a translation to the right by 4 units?

    Thanks in advance
    Blake
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    (Original post by Blake Jones)
    Hi guys,

    I'm revising for the AQA Core 2 exam and came across one I don't understand - I'm not very good at transformations of functions so it might be obvious to you guys.

    If you had a graph and you applied the transformation f(x/2) does this just divide each x value by 2 effectively squishing the graph towards the y axis?
    Also, if you applied the transformation f(4-x) does this just mean a translation to the right by 4 units?

    Thanks in advance
    Blake
    Hi there you replace x with 1/2 x which is a stretch by factor 2 in the x direction.

    For the 2nd transformation, you replace x with 4-x so i believe that is saying -x + 4 so therefore you have reflected the graph in the y-axis and translated it to the left by 4 units. Hope this helps, if you got any other questions/issues be sure to check out by core 2 preaparation thread here: http://www.thestudentroom.co.uk/show....php?t=4104433
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    (Original post by Rager6amer)
    Hi there you replace x with 1/2 x which is a stretch by factor 2 in the x direction.

    For the 2nd transformation, you replace x with 4-x so i believe that is saying -x + 4 so therefore you have reflected the graph in the y-axis and translated it to the left by 4 units. Hope this helps, if you got any other questions/issues be sure to check out by core 2 preaparation thread here: http://www.thestudentroom.co.uk/show....php?t=4104433
    Ah, awesome, thank you
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    (Original post by Blake Jones)
    Ah, awesome, thank you
    No problem, does what i said make sense? I was really intimidated by these types of questions until i really got my head around them so be sure to ask if you still don't understand why the answer is what it is
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    (Original post by Rager6amer)
    For the 2nd transformation, you replace x with 4-x so i believe that is saying -x + 4 so therefore you have reflected the graph in the y-axis and translated it to the left by 4 units.
    This is not correct.

    Reflection in the y-axis would give you f(-x)

    Then if you were to translate that to the left by 4 you would get f(-(x+4)) = f(-4-x)


    Instead write f(4 - x) as f(-(x - 4)) so this is a refelection in the y-axis followed by a translation 4 to the right.
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    (Original post by notnek)
    This is not correct.

    Reflection in the y-axis would give you f(-x)

    Then if you were to translate that to the left by 4 you would get f(-(x+4)) = f(-4-x)


    Instead write f(4 - x) as f(-(x - 4)) so this is a refelection in the y-axis followed by a translation 4 to the right.
    Oh, okay, I think I get that, thanks.
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    (Original post by notnek)
    This is not correct.

    Reflection in the y-axis would give you f(-x)

    Then if you were to translate that to the left by 4 you would get f(-(x+4)) = f(-4-x)


    Instead write f(4 - x) as f(-(x - 4)) so this is a refelection in the y-axis followed by a translation 4 to the right.
    woops you are right haha sorry idk how i missed that :P
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    (Original post by Rager6amer)
    woops you are right haha sorry idk how i missed that :P
    Thanks anyhow, your suggestion was still better than mine!!
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    (Original post by Blake Jones)
    Thanks anyhow, your suggestion was still better than mine!!
    Well at least i showed why you cant rush transformations though, right? Lol :P
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    (Original post by Rager6amer)
    Well at least i showed why you cant rush transformations though, right? Lol :P
    Indeed you did! Haha!
 
 
 
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