Sine of complex numbers.












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It is stated that the system, whose displacement is defined by sin[√(A²-1) + X ], is at rest when A is greater than 0 and smaller than 1.



How can this be shown?










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  • $begingroup$
    At rest when what?
    $endgroup$
    – Jam
    Dec 6 '18 at 19:45










  • $begingroup$
    sorry, it didn't come out right. Is this clearer?
    $endgroup$
    – Mr. Janssens
    Dec 6 '18 at 19:50
















-1












$begingroup$


It is stated that the system, whose displacement is defined by sin[√(A²-1) + X ], is at rest when A is greater than 0 and smaller than 1.



How can this be shown?










share|cite|improve this question











$endgroup$












  • $begingroup$
    At rest when what?
    $endgroup$
    – Jam
    Dec 6 '18 at 19:45










  • $begingroup$
    sorry, it didn't come out right. Is this clearer?
    $endgroup$
    – Mr. Janssens
    Dec 6 '18 at 19:50














-1












-1








-1





$begingroup$


It is stated that the system, whose displacement is defined by sin[√(A²-1) + X ], is at rest when A is greater than 0 and smaller than 1.



How can this be shown?










share|cite|improve this question











$endgroup$




It is stated that the system, whose displacement is defined by sin[√(A²-1) + X ], is at rest when A is greater than 0 and smaller than 1.



How can this be shown?







complex-numbers






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share|cite|improve this question













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share|cite|improve this question








edited Dec 6 '18 at 19:47







Mr. Janssens

















asked Dec 6 '18 at 19:37









Mr. JanssensMr. Janssens

11




11












  • $begingroup$
    At rest when what?
    $endgroup$
    – Jam
    Dec 6 '18 at 19:45










  • $begingroup$
    sorry, it didn't come out right. Is this clearer?
    $endgroup$
    – Mr. Janssens
    Dec 6 '18 at 19:50


















  • $begingroup$
    At rest when what?
    $endgroup$
    – Jam
    Dec 6 '18 at 19:45










  • $begingroup$
    sorry, it didn't come out right. Is this clearer?
    $endgroup$
    – Mr. Janssens
    Dec 6 '18 at 19:50
















$begingroup$
At rest when what?
$endgroup$
– Jam
Dec 6 '18 at 19:45




$begingroup$
At rest when what?
$endgroup$
– Jam
Dec 6 '18 at 19:45












$begingroup$
sorry, it didn't come out right. Is this clearer?
$endgroup$
– Mr. Janssens
Dec 6 '18 at 19:50




$begingroup$
sorry, it didn't come out right. Is this clearer?
$endgroup$
– Mr. Janssens
Dec 6 '18 at 19:50










1 Answer
1






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oldest

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0












$begingroup$

Use the identity $sin(a+ib)=sin(a)cosh(b)+icos(a)sinh(b)$



$implies sin(sqrt{A^2-1}+X)=sin(isqrt{1-A^2}+X)=sin(X)cosh(sqrt{1-A^2})+icos(X)sinh(sqrt{1-A^2})$



Here, $sinh(x), cosh(x)$ are the hyperbolic sine and cosine functions.






share|cite|improve this answer











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    1 Answer
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    0












    $begingroup$

    Use the identity $sin(a+ib)=sin(a)cosh(b)+icos(a)sinh(b)$



    $implies sin(sqrt{A^2-1}+X)=sin(isqrt{1-A^2}+X)=sin(X)cosh(sqrt{1-A^2})+icos(X)sinh(sqrt{1-A^2})$



    Here, $sinh(x), cosh(x)$ are the hyperbolic sine and cosine functions.






    share|cite|improve this answer











    $endgroup$


















      0












      $begingroup$

      Use the identity $sin(a+ib)=sin(a)cosh(b)+icos(a)sinh(b)$



      $implies sin(sqrt{A^2-1}+X)=sin(isqrt{1-A^2}+X)=sin(X)cosh(sqrt{1-A^2})+icos(X)sinh(sqrt{1-A^2})$



      Here, $sinh(x), cosh(x)$ are the hyperbolic sine and cosine functions.






      share|cite|improve this answer











      $endgroup$
















        0












        0








        0





        $begingroup$

        Use the identity $sin(a+ib)=sin(a)cosh(b)+icos(a)sinh(b)$



        $implies sin(sqrt{A^2-1}+X)=sin(isqrt{1-A^2}+X)=sin(X)cosh(sqrt{1-A^2})+icos(X)sinh(sqrt{1-A^2})$



        Here, $sinh(x), cosh(x)$ are the hyperbolic sine and cosine functions.






        share|cite|improve this answer











        $endgroup$



        Use the identity $sin(a+ib)=sin(a)cosh(b)+icos(a)sinh(b)$



        $implies sin(sqrt{A^2-1}+X)=sin(isqrt{1-A^2}+X)=sin(X)cosh(sqrt{1-A^2})+icos(X)sinh(sqrt{1-A^2})$



        Here, $sinh(x), cosh(x)$ are the hyperbolic sine and cosine functions.







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Dec 6 '18 at 20:18









        Tianlalu

        3,08121038




        3,08121038










        answered Dec 6 '18 at 19:59









        Shubham JohriShubham Johri

        4,785717




        4,785717






























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