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    Hey guys could u tell me how to rearrange this. There are 2 rearrangements and ive figured out one of them but cant get the other one cus when i draw the graph its weird lol

    so the equation is 0=5/x^(1/2)+x-7

    ive got x= 7-5/x^(1/2)

    and need help on the other one

    and also guys what does -1<g'(x)<1 mean does tht mean if u put in your starting point and its below 0 the process will converge to a root?

    thnxs
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    (Original post by chuck111)
    so the equation is 0=5/x^(1/2)+x-7
    If I've understood you right: try taking the +x and -7 to the other side, take the reciprocal of both sides, multiply both sides by 5, and square.

    (Original post by chuck111)
    and also guys what does -1<g'(x)<1 mean does tht mean if u put in your starting point and its below 0 the process will converge to a root?
    It just means the derivative of g is always between -1 and 1, in general. Are you talking about some specific iterative process?
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    (Original post by generalebriety)
    If I've understood you right: try taking the +x and -7 to the other side, take the reciprocal of both sides, multiply both sides by 5, and square.


    It just means the derivative of g is always between -1 and 1, in general. Are you talking about some specific iterative process?
    yer im tlaking about the iterative poocess f(x)=0 into g(x) and i need to know about the magnitude of g'x which involves knowing about -1<g'x<1
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    (Original post by chuck111)
    yer im tlaking about the iterative poocess f(x)=0 into g(x) and i need to know about the magnitude of g'x which involves knowing about -1<g'x<1
    There are hundreds of iterative processes. Which one?
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    (Original post by generalebriety)
    There are hundreds of iterative processes. Which one?
    i dunno our teacher jsut said the rearrangement one thts all she said. I know theres newton raphson but in the one were doing it is like when a starting value is chosen a vertical line is drawn from the x-axis to the curve (y=g (x). This line is then continued to the y=x line and from there it is then drawn back to the curve which is the new starting point
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    (Original post by generalebriety)
    There are hundreds of iterative processes. Which one?
    From the sounds of it, he means this one. (Standard C3, if you can remember that far back :tongue:)
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    (Original post by generalebriety)
    If I've understood you right: try taking the +x and -7 to the other side, take the reciprocal of both sides, multiply both sides by 5, and square.
    I did tht and got −0.5√((7−x)/5) is tht correct?
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    (Original post by generalebriety)
    There are hundreds of iterative processes. Which one?
    The one where x_{n+1} = f(x_n).

    Massive OT for everyone else, but if you've done the contraction mapping theorem, the significance of |f(x)| &lt; 1 should become clear...
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    (Original post by DFranklin)
    The one where x_{n+1} = f(x_n).

    Massive OT for everyone else, but if you've done the contraction mapping theorem, the significance of |f(x)| &lt; 1 should become clear...
    hey i was just wondeirng if my rearrangment for 0=5/x^(1/2)+x-7

    is correct: x=−0.5√((7−x)/5)
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    hey i was just wondeirng if my rearrangment for 0=5/x^(1/2)+x-7

    is correct: x=−0.5√((7−x)/5)


    plz i need to know really quickly cus i think i might have dun my c/wk wrong and have to hand it in today (((
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    Is it supposed to be for an iterative procedure?
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    (Original post by stevencarrwork)
    Is it supposed to be for an iterative procedure?
    yes
    is it correct??
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    (Original post by stevencarrwork)
    Is it supposed to be for an iterative procedure?
    it looks like the rearrangement method
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    Where did the 0.5 come from?

    Is the original equation 0 = (5/SQRT(X)) + X - 7

    In which case, surely you just have X = 7 - (5/(SQRT(X))
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    (Original post by stevencarrwork)
    Where did the 0.5 come from?

    Is the original equation 0 = (5/SQRT(X)) + X - 7

    In which case, surely you just have X = 7 - (5/(SQRT(X))
    yes its 0 = (5/SQRT(X)) + X - 7

    and ive already got tht rearrangment 7 - (5/(SQRT(X)) and i need to know if the one i asked for is correct.
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    (Original post by stevencarrwork)
    In which case, surely you just have X = 7 - (5/(SQRT(X))
    He's already found that, he's looking for a second rearrangement (which you wouldn't have known unless you'd read the near identical thread he posted yesterday).

    I've now merged the two threads.
 
 
 
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