how to make a function call with 2 variables of second degree

Hi, how can I make a call function from thes equations. I know how to do it when there is only one variable with second degree but not with 2 variables of second degree.

thanks in advance

Answer 1

[Jan]

Converting a set of ODE functions of a higher degree works exactly the same for 1 or more variables. The procedure remains really simple.

function dy = YourODE(t, y);
y1  = y(1);
dy1 = y(2);
y2  = y(3);
dy  = [dy1; ...
       a * y2 - cos(dy1); ...
       b * dy1 + cos(t)];

See also:

• http://www.sharetechnote.com/html/DE_HigherOrderDEtoFirstOrderDE.html
• https://en.wikipedia.org/wiki/Ordinary_differential_equation#Reduction_of_order

[Jens Petit-jean]

thanks!!