Dear all

I  have a PDE, I would like to substitute the funciton T by another funciton 

How transform the old PDE to a new PDE

transfirm_equation_using_change_variable.mw

thank you

Dear all

I have an equation obtained from partial derivable of some functions, I would like to compute the limit when my variable named Pe goes to infinity. 

I hope to get a more appreciate presentation of my code to obtain the limit (  Pe -> + infty)

limit_infinity.mw

All derivative are well compute, but How can I add the limit as Pe goes to infinity

Thank you 

Dear all

I have a third order equations, I would like to know the sign of its roots, not necessary to find the roots since the equations contains some parameters. All parameters used are positives. 

roots.mw

thank you

Dear all

have a nice time. 

I have a system of nonlinear differential equation with continuous delay.  I tried to find some books that define a strategy to compute the characteristic equation but unfortunattely the most of papers or books give directly the formula without any proof. 

I tried with maple, but unfortunattely no solution up to now. 

I hope find the strategy how find the characteristic equation of the attached system.

characteristic_equation.mw

thanks 

Dear all 
For n geater or equal 2, I would like to solve to find an integrer n that such satisfy an inequality. 

I would like to see how large does n have to be for  the following ineqlaity satisfied. 
But, unfortunattely Maple return 
Warning, solutions may have been lost

restart;
epsilon:=0.001;
solve(10^n /factorial(n) <= epsilon, n);

thank you