Difference between revisions of "Manuals/calci/BESSELY"
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*This function gives the value of the modified Bessel function. | *This function gives the value of the modified Bessel function. | ||
*Bessel functions is also called cylinder functions because they appear in the solution to Laplace's equation in cylindrical coordinates. | *Bessel functions is also called cylinder functions because they appear in the solution to Laplace's equation in cylindrical coordinates. | ||
− | *Bessel's Differential Equation is defined as: x^2 (d^2 y | + | *Bessel's Differential Equation is defined as: <math>x^2 (\frac{d^2 y}{dx^2} + x(dy/dx) + (x^2 - α^2)y =0</math> |
where α is the arbitary complex number. | where α is the arbitary complex number. | ||
*But in most of the cases α is the non-negative real number. | *But in most of the cases α is the non-negative real number. | ||
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*The Bessel function of the 2nd kind of order can be expressed as: Yn(x)=lt p tends to n {Jp(x)Cosp pi()- J-p(x)}/Sinp pi(), where Jn(x) is the Bessel functions of the first kind. | *The Bessel function of the 2nd kind of order can be expressed as: Yn(x)=lt p tends to n {Jp(x)Cosp pi()- J-p(x)}/Sinp pi(), where Jn(x) is the Bessel functions of the first kind. | ||
*This function will give the result as error when 1.x or n is non numeric2. n<0, because n is the order of the function | *This function will give the result as error when 1.x or n is non numeric2. n<0, because n is the order of the function | ||
+ | |||
==Examples== | ==Examples== | ||
Revision as of 04:05, 29 November 2013
BESSELY(x,n)
- Where x is the value at which to evaluate the function and n is the integer which is the order of the Bessel function
Description
- This function gives the value of the modified Bessel function.
- Bessel functions is also called cylinder functions because they appear in the solution to Laplace's equation in cylindrical coordinates.
- Bessel's Differential Equation is defined as: Failed to parse (syntax error): {\displaystyle x^2 (\frac{d^2 y}{dx^2} + x(dy/dx) + (x^2 - α^2)y =0}
where α is the arbitary complex number.
- But in most of the cases α is the non-negative real number.
- The solutions of this equation are called Bessel Functions of order n.
- The Bessel function of the second kind Yn(x) and sometimes it is called Weber function or the Neumann function..
- The Bessel function of the 2nd kind of order can be expressed as: Yn(x)=lt p tends to n {Jp(x)Cosp pi()- J-p(x)}/Sinp pi(), where Jn(x) is the Bessel functions of the first kind.
- This function will give the result as error when 1.x or n is non numeric2. n<0, because n is the order of the function
Examples
- BESSELY(2,3)=-1.127783765(EXCEL)Yn(x)=-0.1070324316(CALCI)Y1(x)
- BESSELY(0.7,4)=-132.6340573(EXCEL)Yn(x)=-1.1032498713(CALCI)Y1(x)
- BESSELY(9,1)=0.104314575
- BESSELY(2,-1)=NAN