@acer 

thanksssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss a lot acer 

You're wonderful

With good luck in life

@acer 

thanksssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss a lot acer 

You're wonderful

With good luck in life

thanks Acer

but your Solution cant solve my problem

my .mw file is : (if you have time see this,thanks)

EKM123.mw

thanks Acer

but your Solution cant solve my problem

my .mw file is : (if you have time see this,thanks)

EKM123.mw

thanks for help acer

my equation is [K].X=0

and for find N , fsolve(Determinant(K))

how to find X ? (X is vector x1,x2,...,x8)

my teacher told NullSpace(K) is wrong Answer ! and said that use another way to find X

indeed my equation is K.X=0

and N is unknown in matrix K and for find X determinate K Must be zero

my teacher told me matrix K is equal to [A]+[B] N+[C] N^(2)+[D] N^(3)+...+[H] N^(8) and in matlab for find N write eig([A],[B],[C],[D],...)  and Eigenvectors is X

@acer

[A]+[B] N+[C] N^(2)+[D] N^(3)+...+[H] N^(8)=0

N is a scalar and unknown and want it ;

thankssssssssssssssssss Preben Alsholm  

how to solve symbolically this equation ??!!!?

 

thankssssssssssssssssss Preben Alsholm  

how to solve symbolically this equation ??!!!?

 

@PatrickT 

sorry PatrickT 

4200000*(diff(T(x, t), t))-0.1e-2*(diff(T(x, t), x))^2-0.1e-2*(diff(T(x, t), x, x))*T(x, t)-.445*(diff(T(x, t), x, x))-158780+4200*T(x, t)-50000/(exp(x))^200

u[0](0.03,t)=37

eval(diff(u[0](x, t), x), x = 0) = 0

u[0](x, 0) = 38.60952381-.3512039716*cosh(64.54972242*x)-.1079529471*sinh(64.54972242*x)+.9128092390*sinh(-1.936491673+64.54972242*x)

EQ.mw

thx Joe and sorry for I can not LIKE you because my Reputation is low !

thx Joe and sorry for I can not LIKE you because my Reputation is low !

why sometime The result is a empty Vectors?

What do in these situations ?

thx.

why sometime The result is a empty Vectors?

What do in these situations ?

thx.

Thx, But I don't know did not solve my problem and the error is high