CriticalPoint Question...

All: I am trying to find the critical points for f(x):=((x-1)^2)^(1/3)-.5*x^2 over [-2, 2] It has two stationary points solve(diff(((x-1)^2)^(1/3)-.5*x^2,x)=0,x); -.5732093133, 1.180229770 and one singular point. 1 But CriticalPoints(((x-1)^2)^(1/3)-.5*x^2, x); only finds -.5732093133, 1 Can anyone explain why? Thanks

make an (animated) plot of a complex function?...

Hello everyone! My question is a stated above... I am trying to find a solution to the wave equation for a standing wave in a rope, with damping. my trial function is : exp(-I*(omega*t+k*x)) * exp(-tau*x) I am still working on my expression for tau, but besides that I have no idea how to plot this. I started to plot exp(-I*(omega*t+k*x)) with omega = 2 and k = 4. I simply can't figure it out, its probebly because it is complex.... Somebody experience with this? already thanks.

Analytic derivatives of numerical solutions of an ...

Hello!

I have a system of ODEs which I can solve numericaly with Maple. What I try to do (still without success) is to compute the i-th derivatives of the solutions at a certain point of the interval. For example (a mini-version):

eq_0 := D(x[0])(t)=(-2*x[0](t))/(1-x[1](t));
eq_1 := D(x[1])(t)=(2*x[0](t))/(1-x[1](t));
sys := {eq_0, eq_1, x[0](0)=1, x[1](0)=0};
fcns := {x[0](t), x[1](t)};
p:=dsolve( sys, fcns, numeric, method=classical[rk2], output=listprocedure );

(OK, this is very easy, but it is only an example.)

Now I want to compute the 6-th derivative of x[0](t) at t=1/2. The analytic form can be obtained if D(x[0]) is differentiated 5 times and x[0] and x[1] are substituted by their numerical solution. I have read about differantiating in Maple, but I still cannot get this work.

Sign of a polynomial...

Hi -- I want to check the sign of a polynomial. Here's the polynomial expression (1/16)*(9*s^5-3*s^4*m-34*s^4*pa+12*s^3*m*pa+46*s^3*pa^2-18*s^2*m*pa^2-24*s^2*pa^3 +12*s*m*pa^3+s*pa^4-3*m*pa^4+2*pa^5-16*s^4+64*s^3*pa -96*s^2*pa^2+64*s*pa^3-16*pa^4+16*p^2*s+48*p^2*m-64*p^2*pa)/(s-pa)^4 and here's the parameterization: pa>s and pa>m. Generally checking the sign of the polynomial involves checking the signs of the factors...so, I'd like to factor the above expression. I haven't worked with "factor" much in Maple. Applying it as just factor(expr) with expr equal to the above expression does nothing. So not sure the best approach.

obtaining distributions...

Hello again Maple experts, I have four nonstochastic variables s11, s12,s21,s22.. from there I have 2 random variables X1 and X2 (to begin, it may be a uniform distribution U[-1,1]) . I generate the random variables y1 and y2: y1 = min(s11+X1, s21+X2) y2 = min(s12+X1, s22+X2) 1. How could I obtain with MAPLE the distribution of Z= (y1)^(1/2)+log((40-y2)*(80+2*y2-3y1))? 2. And how could I obtain the expected value of Z? Thanks in advance for any help. Regards, Jean

can't use map on nested lists...

I have a nested list, say test:=[[1,2,3,4],[5,6],[7,8,9]]: and I want to use something like map(x->1/x,test); to get [[1, 1/2, 1/3, 1/4], [1/5, 1/6], [1/7, 1/8, 1/9]] but it won't work... map doesn't go in nested lists and it rather returns [1/[1, 2, 3, 4], 1/[5, 6], 1/[7, 8, 9]] I can't find an example about this simple problem, I'm sure it must be easy though but I'm losing my mind on this one.

Euler's Method...

Hi, I have been trying to use Euler's method to calculate approximate values on maple 11, and I cannot get it to work. Can someone show me the exact things to enter? I am given y', an initial value, and step size. I looked it up online and followed various directions, but still haven't been able to get an answer.