MATLAB Answers


Solving for a variable with varying parameters in the sum

Asked by NN
on 21 Mar 2019
Latest activity Commented on by NN
on 22 Mar 2019
being the unknown variable, how to initialize and write the following equation in matlab script containing varying paramters.
(n = 0,1,2,...)


Tried implementing using symbolic variables. It gets complicated and confusing considering the summation and varying m as well as n values.

Sign in to comment.




1 Answer

Answer by Walter Roberson
on 21 Mar 2019
 Accepted Answer

You cannot. That describes an infinite summation where you need to solve all infinite I_m values.
You cannot truncate it because truncation would imply that if you were to make some I_m indefinitely big for some "large" m, that it would not make a substantial difference to the summation -- but clearly if you know the a_m c_m_n R_m_n values then you can create a corresponding I_m value that overwhelms any previous sum you might have had.


You also have an infinite number of equations - one for each n.
Such problems usually arise if one wants to determine the coefficients of the power series of the product or the quotient of two functions from which the power series are known.
What about if instead of a finite number was used, like so:
(n = 0,1,2,...)
As or your second comment, , and have known relations but contain varying parameters too. For example \alpha_m from the above equation = , where π and a are known constants.
How do you intend to exclude the trivial solution I_m = 0 for all m ?

Sign in to comment.