## statistics...

I need help with this problem !!!!!!!!   My brain is turning to mashed patato's  Thank-You

In a study on infants, one of the characteristics measured was head circumfrence. The mean head circumference of 15 infants was 34.6 centimeters (cm).

## Statistics...

The data in the table represents the ages of the winners of an award for the past five years. Use the data to answer questions (D) and  (E)

39     40

-------------

48     48

-------------

42

## Taylor Expansion Of Cot(x)...

A problem instructed me to construct a Taylor/Maclaurin series for cot(x) by dividing cos(x) by sin(x).

I did this quotient by putting both summations over each other then cancelling common terms.

I've always had some difficulties with summation, or the rules of the summation symbol and would like to know if that operation was legal.

In this case both summations began from the same starting point for the dummy variable, n.

Whenever this is the case is it correct to say that the quotient of two sums is the sum of the quotient?

very respectfully,

## Roots of the derivative of Bessel function of the ...

I've been trying to vreate a script which will provide the roots of the Bessel function of the first kind, and it's derivative.

The root of the Bessel itself is fairly straight forward, simply BesselJZero(m,n); however, I can't do the same for the derivative diff(BesselJ(m,n),n).

Any help would be appreicated.

## Statistics...

A population has a mean of 75 and a standard deviation equal to 21. Find the mean and standard deviation of a sampling distribution of a sample means with a sample size of 49.

## stop_cond question...

I am using dsolve to integrate a system of equations, and I am using stop_cond to stop the integration when certain conditions are met.

The problem is, I want the integration to stop when condition 1 AND condition 2 are met, but when I use, for example

stop_cond=[y(t)-2,t-4]

it stops as soon as ONE of these conditions are met, not both. I want it to stop when y(t) is equal to 2 AFTER t=4, not before.

Any suggestions would be greatly appreciated!

## nice looking superscripted Arrows ?...

Hi, i just want to write this equation im Maple,  how do i do it ?

thanks

## Solving systems of polynomial equations...

Hi

I'm trying to find all solutions to a system of polynomial equations. I've tried using Isolate from the RootFinding package and for some choice of parameters this works well. However changing the parameters (i.e changing some of the coeffients of the polynomials), I get the error message.

Error, (in RootFinding:-Isolate) decreasing address previous=1e0f0020 new=10010020!

Any ideas on what this means?  possible ways around it? or other functions in maple that would give me all solutions?

Thanks, Steve.

## color function in plot3d...

I am trying to color  3D plots according to phase using color=argument(x)/Pi/2

I get different results depending on the form I enter the expression x, as shown on the worksheet. Any suggestions to make this consistent?

## How does Maple find limit and how to define/assume...

I was testing if Maple can prove/show limit(a*(1-F(a)), a=infinity,left)=0, where F(.) is a general cumulative distribution function. Though, I doubt Maple has the ability.  However, I come across with some other questions during the exploration:

1. how is maple exactly doing to find limit:
Let's first try a normal distribution case:

with(Statistics):
U := RandomVariable(Normal(s,t))  :
limit(CDF(U,x),x=infinity,left)  assuming t>0,t<infinity ;

## Paragraph styles - some won't work...

Is there an explanation on how each of the different paragraph styles work?

I was experimenting the other day and some selected paragraph styles don't allow you to type any text at all.  Couldn't find anything in the help pages, or I might have just been looking in the wrong area.

## MY MAPLE WORKSHEET IS VERY VERY VERY SLOW: can you...

Hi to everybody.  I have to manipulate a system of partial differential equation,one by one.I have in particolar to derive a lot of time my differential equations(shallow water equations),and then to group, to substitute and at the and I need time derivative in function of spatial derivative.

I'm almost done. The problem is that now every time that  I execute a command it takes  a lot of time. The entire file takes some minuts to compile. It's so slow.

## Runge-Kutta of order 2 does not evaluate...

Hi all,

Suppose that you want to solve x'(t)=f(x,t)   x(t0)=x0

The theory show that:

x(t+h)=x(t)+1/2*h*(F1+F2) where F1=f(x,t) and F2=f(x+F1,t+h)

## implementing switch/case?...

Is there a switch/case statement in Maple?  So that instead of:

if (a = a1) then

b1

elif (a = a2) then

b2

elif (a = a3) then

b3

end if

Something like:

switch (a) {

case: a1 {b1}

case: a2 {b2}

case: a3 {b3}

}

???

I'm potentially going to have a long list of elif's and might need  more efficient way of doing it.