parametrization of a circle given a property












2












$begingroup$


Provide a parametrization with the given properties:



The curve is circled at point $(a, b)$. It is traced once counterclockwise, starting at the point $(a+r, b)$ with $t in[0,2π]$



attempt:



$x = a + r cos(t), y = a+rsin(t)$ for $t in [0, 2pi]$



is above not right?










share|cite|improve this question









$endgroup$












  • $begingroup$
    I believe your second equation should be $y = b + rsinleft(tright)$, but otherwise everything else looks fine to me. Also, with your second line starting with "The curve is circled at ...", I assume "circled" is meant to be "centered".
    $endgroup$
    – John Omielan
    Jan 22 at 1:05












  • $begingroup$
    Yes it is correct if you change a to b in y.
    $endgroup$
    – lightxbulb
    Jan 22 at 1:05


















2












$begingroup$


Provide a parametrization with the given properties:



The curve is circled at point $(a, b)$. It is traced once counterclockwise, starting at the point $(a+r, b)$ with $t in[0,2π]$



attempt:



$x = a + r cos(t), y = a+rsin(t)$ for $t in [0, 2pi]$



is above not right?










share|cite|improve this question









$endgroup$












  • $begingroup$
    I believe your second equation should be $y = b + rsinleft(tright)$, but otherwise everything else looks fine to me. Also, with your second line starting with "The curve is circled at ...", I assume "circled" is meant to be "centered".
    $endgroup$
    – John Omielan
    Jan 22 at 1:05












  • $begingroup$
    Yes it is correct if you change a to b in y.
    $endgroup$
    – lightxbulb
    Jan 22 at 1:05
















2












2








2





$begingroup$


Provide a parametrization with the given properties:



The curve is circled at point $(a, b)$. It is traced once counterclockwise, starting at the point $(a+r, b)$ with $t in[0,2π]$



attempt:



$x = a + r cos(t), y = a+rsin(t)$ for $t in [0, 2pi]$



is above not right?










share|cite|improve this question









$endgroup$




Provide a parametrization with the given properties:



The curve is circled at point $(a, b)$. It is traced once counterclockwise, starting at the point $(a+r, b)$ with $t in[0,2π]$



attempt:



$x = a + r cos(t), y = a+rsin(t)$ for $t in [0, 2pi]$



is above not right?







multivariable-calculus






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share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Jan 22 at 0:59









TinlerTinler

558314




558314












  • $begingroup$
    I believe your second equation should be $y = b + rsinleft(tright)$, but otherwise everything else looks fine to me. Also, with your second line starting with "The curve is circled at ...", I assume "circled" is meant to be "centered".
    $endgroup$
    – John Omielan
    Jan 22 at 1:05












  • $begingroup$
    Yes it is correct if you change a to b in y.
    $endgroup$
    – lightxbulb
    Jan 22 at 1:05




















  • $begingroup$
    I believe your second equation should be $y = b + rsinleft(tright)$, but otherwise everything else looks fine to me. Also, with your second line starting with "The curve is circled at ...", I assume "circled" is meant to be "centered".
    $endgroup$
    – John Omielan
    Jan 22 at 1:05












  • $begingroup$
    Yes it is correct if you change a to b in y.
    $endgroup$
    – lightxbulb
    Jan 22 at 1:05


















$begingroup$
I believe your second equation should be $y = b + rsinleft(tright)$, but otherwise everything else looks fine to me. Also, with your second line starting with "The curve is circled at ...", I assume "circled" is meant to be "centered".
$endgroup$
– John Omielan
Jan 22 at 1:05






$begingroup$
I believe your second equation should be $y = b + rsinleft(tright)$, but otherwise everything else looks fine to me. Also, with your second line starting with "The curve is circled at ...", I assume "circled" is meant to be "centered".
$endgroup$
– John Omielan
Jan 22 at 1:05














$begingroup$
Yes it is correct if you change a to b in y.
$endgroup$
– lightxbulb
Jan 22 at 1:05






$begingroup$
Yes it is correct if you change a to b in y.
$endgroup$
– lightxbulb
Jan 22 at 1:05












1 Answer
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0












$begingroup$

We have a circle of equation:



$$(x-a)^2+(y-b)^2=r^2$$



Setting $x=a+rcos(t)$ and $y=b+rsin t$ gives:



$$(rcos(t))^2+(rsin(t))^2=r^2$$



$$to r^2(cos^2(t)+sin^2(t))=r^2$$



which holds because $cos^2(t)+sin^2(t)=1$



So your mistake was simply you need $y=b+...$ rather than $y=a+...$






share|cite|improve this answer









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    1 Answer
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    1 Answer
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    0












    $begingroup$

    We have a circle of equation:



    $$(x-a)^2+(y-b)^2=r^2$$



    Setting $x=a+rcos(t)$ and $y=b+rsin t$ gives:



    $$(rcos(t))^2+(rsin(t))^2=r^2$$



    $$to r^2(cos^2(t)+sin^2(t))=r^2$$



    which holds because $cos^2(t)+sin^2(t)=1$



    So your mistake was simply you need $y=b+...$ rather than $y=a+...$






    share|cite|improve this answer









    $endgroup$


















      0












      $begingroup$

      We have a circle of equation:



      $$(x-a)^2+(y-b)^2=r^2$$



      Setting $x=a+rcos(t)$ and $y=b+rsin t$ gives:



      $$(rcos(t))^2+(rsin(t))^2=r^2$$



      $$to r^2(cos^2(t)+sin^2(t))=r^2$$



      which holds because $cos^2(t)+sin^2(t)=1$



      So your mistake was simply you need $y=b+...$ rather than $y=a+...$






      share|cite|improve this answer









      $endgroup$
















        0












        0








        0





        $begingroup$

        We have a circle of equation:



        $$(x-a)^2+(y-b)^2=r^2$$



        Setting $x=a+rcos(t)$ and $y=b+rsin t$ gives:



        $$(rcos(t))^2+(rsin(t))^2=r^2$$



        $$to r^2(cos^2(t)+sin^2(t))=r^2$$



        which holds because $cos^2(t)+sin^2(t)=1$



        So your mistake was simply you need $y=b+...$ rather than $y=a+...$






        share|cite|improve this answer









        $endgroup$



        We have a circle of equation:



        $$(x-a)^2+(y-b)^2=r^2$$



        Setting $x=a+rcos(t)$ and $y=b+rsin t$ gives:



        $$(rcos(t))^2+(rsin(t))^2=r^2$$



        $$to r^2(cos^2(t)+sin^2(t))=r^2$$



        which holds because $cos^2(t)+sin^2(t)=1$



        So your mistake was simply you need $y=b+...$ rather than $y=a+...$







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Jan 22 at 1:15









        Rhys HughesRhys Hughes

        6,9741530




        6,9741530






























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