Dear all

I have a system of differential equation with initial condition. 
I try to get the exact solution bur unfortunattely dsolve does not return the exact solution of my system 

SSDE.mw

Thank you 

Dear all 
I need the sign of eigenvalue of the given marrix.
Note that it is not essay to compute the eigenvalues but we can use  ROUTH Hurwitz criterion that give the sign of eigenvalues without computing them

stability.mw

Thank you 

Dear all 

I have a function defined on many sub-intervals, how can I simplify this the funciton obtained at each iteration. I hope obatin B_{i,1}, B_{i,2}, and B_{i,3} 

B_Spline.mw

Thank you 

Dear all

I would like to get the solution of a system : pde with boundary and initial condition. Everything well coded, but the code does not return the solution 

sol_heat.mw

Thanks for your help 

Dear all

I have a first sequence alpha, I would like to define a second sequence beta using a general formula of beta[i]

sequence.mw

Thank you