By setting e.g. gamma=1 as here:

sys:={-.5/(k^.36*(h[1]+h[2])^.64-c[2]+8.975*k)+.5/c[2] = 0, 
.64*k^.36/((k^.36*(h[1]+h[2])^.64-c[2]-0.25e-1*k)*(h[1]+
h[2])^.36)-2*(1-h[1])^(-gamma) = 0, .320*k^.36/((k^.36*(h[1]+
h[2])^.64-c[2]-0.25e-1*k)*(h[1]+h[2])^.36)-1.0+1.0*h[2] = 0, 
.5/(k^.36*(h[1]+h[2])^.64-c[2]-0.25e-1*k) = (.495*(.36*(h[1]+
h[2])^.64/k^.64+.975))/(k^.36*(h[1]+h[2])^.64-c[2]-0.25e-1*k)}:

solve(subs(gamma=1,sys));

I get a long sequence of equation sets.

Something like:

sys:={A*(diff(xx(t), t)) + epsilon*xx(t) + 
B*(diff(phi(t), t))*cos(theta(t)) + C*phi(t)^2*sin(theta(t)) = F(t),
DD*(diff(xx(t), t))*cos(theta(t)) + E*diff(phi(t), t) + 
F*sin(theta(t)) = 0,
xx(t) = diff(x(t), t),
phi(t) = diff(theta(t), t)}:

IC:={x(0)=0,xx(0)=1,theta(0)=1,phi(0)=0}:

sol:=dsolve(eval(sys,[F=0,A=1.1,B=.5,C=.3,DD=1.9,E=3,epsilon=.2]) 
union IC,numeric):
plots:-odeplot(sol,[x(t),phi(t)],t=0..5);

For segments (not vectors) see this example.

As far as I know, it is impossible to disable automatic simplification in Maple. It is possible to switch it off in Maxima.

Aladjev's library difff can be used:

difff(5*x^2+y, x^2);
                                  5

It works also in one of Alec's examples:

difff(x^4, x^2);
                                    2
                                 2 x

difff(1/x^2, x^2);
Warning, zero value can be conditioned by inadequacy of substitutions

                                  0

(this is in Maple 10.06)

See also ?PDEtools,diff_table

v:=<5*t+1, (1/2*(-10))*t^2+50>:
VectorCalculus:-BasisFormat(false):#optional control of display
VectorCalculus:-diff(v,t);

		MATRIX([[5], [-10*t]]); 

One thing that you can do is:

evalc((a+b*I)^k+(a-b*I)^k):
collect(%,exp,expand):
simplify(%) assuming positive; 

                     2    2 (k/2)
                 2 (a  + b )      cos(k arctan(b/a))

You can write a simple procedure, based on complexplot3d, to plot the real and imaginary parts of a function together:

cplot:=proc(f,x,r)
 local re,im:
 re:=plots:-complexplot3d([Re(f),.4],x=r,axes=boxed):
 im:=plots:-complexplot3d([Im(f),1],x=r,axes=boxed):
 plots:-display([re,im]);
end proc:

cplot(sin(z),z,-2-2*I..2+2*I);

Just do not take into account the label |z|.

It would help if you post the complete sequence of statements. What is E, Ep, etc.

Yes, I have observed similar problems before. May be the graphics card and/or its  driver. I think that Ubuntu 9.04 is not officially supported, but may be that you could get some hint from support.

What do you mean exactly by solve by hand. This system has 5 equations and 11 unknowns:

eqs:={z1s- p*y1s-(1-p)*y1=0, z2s- p*y2s-(1-p)*y2=0, z3s- p*y3s -
(1-p)*y3= 0, y1s+y2s+y3s=1,   y1s-thetas1*(1- z1s-z2s) -
(1-thetas1)*z1s=0 } :
nops(eqs);
indets(eqs);nops(%);
                                  5

        {p, y1, y1s, y2, y2s, y3, y3s, z1s, z2s, z3s, thetas1}

                                  11
 

Read ?UserLib!!!

Because you assign to  param a list of equations like L[1] = 30.0*Unit('ft'), but L[1] does not get a value because of that. You can use though:

subs(param,L[1]);
                           30.0 Units:-Unit('ft')

Do you mean the Typesetting code?