Question: How to use a result of the function as a known parameter?


for example,i have already got the odeplot of function m(t),n(t).  And now i want to use the value of m(t) to calculate function x(t),y(t).

eq1:=diff(x(t),t)=m(t)*cos(y(t))-n(t)*sin(y(t));  #The function of x(t):

eq2:=diff(y(t),t)=m(t)*sin(y(t))+n(t)*cos(y(t));  #The function y(t):



but i got an Error

Error, (in dsolve/numeric/process_input) unknown m present in ODE system is not a specified dependent variable or evaluatable procedure.

But before this i have already got the odeplot of function m(t) and n(t),how can i solve this problem?

Please Wait...