@Kitonum thank you so much , 

but who can find 

(2) Let v = 8t^2- 4t + 6 and w = 7t^2- t + 9. Find the coordinates for

v and w with respect to the basis L1 and with respect to the basis L2

Thanks Kitonum 3505

I write now correctly can you help me ?

@Carl Love 

Thank you

Can you explain the animate and why separation of variable always satisfies the boundary conditions

@Joe Riel 

Thank you

But the last step does not give me a correct answer?

@Carl Love 

Thank you

But can you explain the first step because I do not understand OrthogonalExpansions ?

Can you change the fisrt step?

@J4James   

Thank you.

Your answer help me so much.

But can  you explain  every steps?

 Also what is the meaning of the PDE,BCs,pde and pdsolve? Do they have special meaning in the Maple or not ?

I would strogly appriciate your help

@mehdi jafari  

Thank you.

Your answer help me so much.

But can  you explain  every steps?

 Also what is the meaning of the PDE,BCs,ans,pDS and toois ? Do they have special meaning in the Maple or not ?

I would strogly appriciate your help

@Carl Love 

Hi Carl

I am sorry, I thought I only have This space to write my question.

I opologize, and thank you so much for you help