How do I calculate the derivative of C(r,t) with respect to r evaluated at r=a? I can do it in multiple lines like this:

temp:=diff(C(r,t),r);

r:=a;

R:=temp;

r:='r';

But this is a pretty ghetto way of doing this, how do I solve for R in one line? I thought diff or D could do it but I can't seem to get the syntax right :(

Thanks.

From the program below

Dear all,

 How How to plot curves family in one picture in Maple? For example

the curves family are y=a*x^2+5 
with a={4,8,12,16} 
and  x is in the region [-5, 5]

Thanks

Greetings all restart; f := x->x^4: assume(n::integer): an := 1/Pi*int(f(x)*cos(n*x),x=-Pi..Pi): FaN1 := sum(an*cos(n*x),n=1..N); FaN2 := Sum(an*cos(n*x),n=1..N); On Maple 13, FaN1 and FaN2 are very different representations of this series. However, on Maple 11 they are the same (same as FN2 on Maple 13). How can I persuade Maple 13 to convert FaN2 to FaN1 ? Also, how can I persuade Maple 11 to convert aFN1 to FaN2 ?

given this equation: f(x,y) = (xysin(x-y)) / (1+(x^2)+(y^2)) , for (1,1,0) i need to compute the partial derivatives and graph the surface and the tangent plane at the given point. this is as far as i got before getting stuck > f := xysin(x-y)/(1+x^2+y^2); xysin(x - y) ------------ 2 2 1 + x + y > plot3d(f, x = -3 .. 3, y = -3 .. 3, grid = [2, 2]);

restart; with(DEtools) x1 := diff(x(t), t) = (4-x-4*y)*x; y1 := diff(y(t), t) = (4-4*x-y)*y; phaseportrait([diff(x(t), t) = (4-x-4*y)*x, diff(y(t), t) = (4-4*x-y)*y], [x(t), y(t)], x = -20 .. 20, y = -20 .. 20, t = -2 .. 2, [[x(0) = 0, y(0) = 1]], stepsize = 0.5e-1, scene = [y(t), x(t)], linecolour = sin((1/2)*t*Pi), method = classical[foreuler]) I'm trying to specify the domain for x and y but I receive the following error Error, (in DEtools/phaseportrait) initial conditions must be specified in inits The above works when I get rid of x = -20 .. 20, y = -20 .. 20,

 How do I get both branches (i.e. positive and negative values) for f(x) on the same plot of f(x) = x^(1/2)?

 

Thanks very much,

Greg

Hi,

I have a frustrating error that comes from using Code generation with diff

It works fine when processing a single equation but doesn't like matricies:

> Xx := ((cos(q1)*cos(q2)+0.8e-3*sin(q1)*sin(q2))*sin(q3)+(0.8e-3*(-cos(q1)*sin(q2)+0.8e-3*sin(q1)*cos(q2)))*cos(q3)+sin(q1)*cos(q3))*L3+(0.8e-3*(cos(q1)*sin(q2)-0.8e-3*sin(q1)*cos(q2)+0.8e-3*sin(q1)))*L3+sin(q1)*(L21+L22);

I would like to calculate engineering stress using array; but the following piece of codes do not seem to work. *EngineeringStress = force / area *Define force is an array of measurements of force. crossArea:= 3.2 * 19.1 (not the "*" is really a "." in Maple editor; it is multiplication) force := array ([0., 1380.0, 2780.0, 5630.0]) engineeringStress := force/crossArea; engineeringStress[1] ({0., 1380.0, 2780.0, 5630.0}/crossArea)[1] it suppose to be 0!!!

When i input something like sqrt(30) I just get back 30 with a square root symbol over it. How can I make maple evaluate it?

How do I generate a gaussian random matrix (2x2).

Is this the default setting already in maple or is there code I need to use?

I'm to generate a random matrix ie > with(LinearAlgebra); > RandomMatrix(2, 2, generator = -1 .. 1); and find the eigenvalues of each matrix ten times. How do I put random Matrix in the for loop with Maple?

I have two vector here

X:= vector([-1,0,1])

Y:=vector([1+I*2,3+I,4+3*I], datatype=complex)

I want to fit them in the form a*exp(-I*10*t)+b*exp(I*10*t), a and b may be complex.

How should I do?

I have two vector here, and I want to fit them with the form a*exp(-I*4375*t)+b*exp(I*4375*t), a and b should be complex. How should I do?

X := Vector([-0.000163, 0, 0.000163], datatype = complex);

Y := Vector([-8.84352*10^(-13)+(I*1.71511)*10^(-12), 1.49867*10^(-13)+(I*1.45355)*10^(-12), 1.15763*10^(-12)+(I*9.08261)*10^(-13)], datatype = complex[8]);
 

 

The following interaction with Maple's Excel link came to my attention today.  I thought it had many interesting points that lead to insights about Excel and Maple that are worth sharing.