I need help solving the following integral with Maple

int(erfc((R+3*t)/(6*t^1/2)),t=0..1)

I have a new one :) I need to find the critical points and tell their nature of a 3 variable function. It's a new thing for me and i'm not sure if i did it ok, here's what i have tried:

g := 1-2*x+3*x^2-x*y+x*z-z^2+4*z+y^2+2*y*z;

ex := extrema(g, {}, {x, y, z}, 't'); - stores the extreme value of f in ex

evalf(ex); - displays the extreme value in decimal

t; - contains the critical points of f

evalf(t); - displays the critical points in decimal

Here's what i have to do. i have a system formed of 3 equations, and i have to find the solutions ( there may be only one ), and the make sinus out of it evaluating it with 5 digits.

I am finding problems with plot first:

I am trying to find out all the real solutions of a system of 2 eqns and i just can't figure it out. Here's what i'm trying:

>eqn1:=x+y=9;

eqn2:=x+y-sin(x*y)=7;

solve({eqn1,eqn2})

 

After i hit enter, i get this warning:

 

Warning, solutions may have been lost

 

I'm completely lost !:(

 

Dear all:

   I assume this is an easy question, but I simply couldn't find an answer: How to sample from a multivariate normal distribution give a mean M and covariance matrix Ccov? The statistics package seems to only contain 1-d distributions.

Thanks a lot,

Peter

plot (arccos(cos(x)),x);

At x=0, arccos(cos(x)) should be shown on the graph at (0,0),  As I zoom in I find that Maple draws it at closer to the point (.01,-.01) not at all at (0,0)

How do I create 3D polygone by a list of points using maple.?

I convert following differential equation to the s domain: restart: with(inttrans): > DV:=diff(y(t),t$2)+3*diff(y(t),t)+2*y(t)=diff(x(t),t): > x:=t->10*exp(-3*t): > laplace(DV,t,s); As solution I get: s^2*laplace(y(t),t,s)-D(y)(0)-s*y(0)+3*s*laplace(y(t),t,s)-3*y(0)+2*laplace(y(t),t,s) = -30/(s+3) It's not really a Maple problem but I don't understand why the right hand side of the equation is -30/(s+3) . When I transform the right hand side of the differential equation manual to the laplace domain I would do it as: diff(x(t),t) = s*X(s) = s * 10 /(s+3)

Is there a way to solve following equation in maple? I have already tryied intsolve and dsolve without succes. DV:=diff(y(t),t)+5*int(cos(t-tau)*y(tau),tau=0..t)=10; Thank you, Pieter

An annoying feature of Maple is that if it crashes (all too often) & you have not given your worksheet a name, the file is lost despite having activated Auto-Save.

1)   Is the previous statement correct for Maple 9.5?

2)   If so, has this bug been corrected in later versions?

Alla

I create a continous random variable having an arbitrary pdf and characterize the corresponding distribution:

pdf := piecewise(a <= x and x <= b, 1, 0): f := unapply(pdf, x): R := Statistics:-RandomVariable(Statistics:-Distribution(PDF = f)): `assuming`([map(apply, [Statistics:-MGF, Statistics:-CGF, Statistics:-PDF, Statistics:-CDF, Statistics:-Moment], R, t)], [a < b]) ;

Hello,

I have a big problem with the plot command :

I have tried to do a densityplot with cylindrical coords, but it doesn't work, it seems that maple can't do it. Do you have any suggestion to do this ?

So I decided to switch to plot3d - contourplot even if i would rather like densityplot. The problem is that i can't show the whole plot : maple only shows me a quarter of what i want :

contourplot( f (r,alpha), r=0..5, alpha = 0..2*Pi, coords=cylindrical );

where is the rest of the function ?

gerald

thanks for your help !

Hello,

I'd like to create a multiple variables function with a procedure, the problem is that the number of vars depends on the parameter n :

f:=(x1, x2, ..., xn) -> ...

how to define this function ?

 

I ve tried to do this, but i doesn't work :

var:=seq(d[i],i=1..n)
f:=(var)-> ...

even with a array instead of the seq, it doesn't work ... i'm desperate

 

thanks !

I've been trying to solve Project Euler's first problem: If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23. Find the sum of all the multiples of 3 or 5 below 1000. I've come up with: natural:=proc(n); local i,s; s:=0; for i from 1 to n do if irem(i,3)=0 or irem(i,5)=0 then s:=s+i fi od; return s; end; but I also get the error message: "Error, unexpected `local` declaration in procedure body" Could you please tell me where I've gone wrong? Thanks in advance

Hi everybody:

Concerning exporting a worksheet as RTF (Maple12, win XP) I note two things: a) if you use inline output things such as equal sign, arrow with "at 5 digits" text, etc. appear slightly higher than the rest of the expression. also some part of the output is chopped off. b) the labels don't export.

Are these things consistent with what you could currently expect from maple or am I missing something?

thanks

Dimitrios