i have three nonlinear pde equations and i want to solve them,with any initial or boundary condition possible,can anyone help me solve them?
it is of no importnace to solve them numerially or not. 

i had 3 nonlinear equations and i want to convert them to the form of multiplications of a MATRIX in a VECTOR, but none of these two methods give me the right answer,what should i do?

#method one#

restart:
with(LinearAlgebra):
eq1:=a[1]+a[2]*a[3]^2*a[1]+a[2]*a[3]-a[1]^2:
eq2:=a[3]+a[1]^3+a[2]*a[3]+a[2]^2-a[1]^2:
eq3:=a[1]^3+a[2]^3+a[1]*a[2]*a[3]+a[1]*a[2]-a[3]:
for i to 3 do
B || i := eq || i ; K || i := Vector[row](3):
for j to 3 do

how can i define a matrix as a sunction of a variable so that when i chande the independet variable,the elements of the matrix also change?

A(t):=[a[t],b[t],c[t]] ; i want to define a function like this,so that by changing the time t,the elements of the matrix also change,what should i do?

i have a very simple question that has made trouble for me,how can i factor this easy expression with respect to x?

nn := .1689228391e12*x^2-5539558.102*a[17][t]*x+23266721.99*a[18][t]*x+9251036.956*a[15][t]*x-6275707.162*a[16][t]*x+.4614468816e11*x*a[14][t];

factor(nn);

collect(nn,x,factor);

non of these expressions does not give me the answer which i want, i just want to write this expression in this way :

nn:=x*(...);

could anyone help me?thnx. 

how can i convert these equations to the vector mode ? 

eq1[t] := .4614468816e11*a[13][t]*a[14][t]+2291210.983*a[16][t]^2-.2842690977e11*a[17][t]^2-.1782456232e12*a[18][t]^2+.1689228391e12*a[13][t]^2+6406045.412*a[14][t]^2-4317791.317*a[15][t]^2+.9846526429e12*a[1][t]+.2533881291e12*a[2][t]+.3076607771e11*a[3][t]+8105875.203*a[4][t]-5054889.363*a[5][t]-34561.30764*a[6][t]-6275707.162*a[16][t]*a[13][t]-20873274.82*a[14][t]*a[16][t]-27435155.86*a[16][t]*a[15][t]-5539558.102*a[17...