Mariner

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18 years, 104 days

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These are answers submitted by Mariner

Mario,

Please see the help page by entering ?int. This gives an example of a double integral. In future it would be easier to understand what help you need if you could  write out your problem more fully.  Guessing at what your first example means, I tried this:

restart;
Int( Int(x^2 + y^2,x=y-a..y), y=3*a..a);
value(%);
 

Hope this helps,

J. Tarr

Please see the help page ?dsolve and its examples.

Hope this helps.

J. Tarr

Chen,

You might find http://integrals.wolfram.com/index.jsp useful. It's free and you will need pencil, paper and a little thought to get the answers you want.

For example

Int(exp(x^(-2), x) is given as (1/2)*sqrt(Pi)*erf(x).

Since erf(infinity) = 1 and erf(0)=0, the answer you want is

(1/2)*sqrt(Pi)

Hope you find this helpful.

J. Tarr

Please see ?Statistics[ExponentialFit] and first example. ExponentialFit tries to fit y = a * exp(b * x) to the data. It doesn't necessarily produce a good fit - in your example LeastSquares(x,y,t,curve=a*exp(-t) + b*t +c produces a better fit.

Hope this helps.

J. Tarr

Please see ?PDEtools[declare].

Hope that's what you need.

J. Tarr

Please see third example at ?CurveFitting[LeastSquares].  I assume that you want to use an exponential as your curve.  If so try this:

restart;
x := <0.0, 1.0, 2.0, 3.0, 4.0, 5.00, 6.00, 7.00, 8.00, 9.0>:
y := <4.1, 1.3, 0.4, 0.3, 0.1, 0.08, 0.07, 0.06, 0.08, 0.1>:
p1 := plots:-pointplot([seq([x[i],y[i]],i=1..9)]): ##Plot points(Measured values )
sol2 := CurveFitting:-LeastSquares(x,y,t,curve=a*exp(-t) + b*t +c): ## get optimal val
p2 := plot(sol2,t=0..8):
plots[display]([p1,p2]);
 

Hope this helps.

 

J. Tarr

Please see ?plots[display] second calling sequence and examples with Arrays of plots. Something like this should do what you want:

A := Array(1..2):
A[1] := inequal({x-y <= 1, x+y > 0}, x = -3 .. 3, y = -3 .. 3, optionsfeasible = (color = red)):
A[2] := inequal({y < 0, x < 0}, x = -3 .. 3, y = -3 .. 3, optionsfeasible = (color = blue)):
display(A);
 

J. Tarr

Do you want to differentiate

y(x)^2+(x-c)^2=c^2 w.r.t.  x ? Try

diff(%,x).

J. Tarr

Try this

Int( (sin(x))^2/x^2, x=-infinity..infinity);
value(%);

Perhaps your limits are wrong.

J. Tarr

Take a look at the Maple Application Center in the section Science:Chemistry and you should find something to get you started. Good luck,

J. Tarr

If you assign your equation to eq, you could use fsolve, like this

fsolve(eq,{P},P=0..2);

     {P=0.527727062715}

Hope this helps

J. Tarr

The html tags have messed up Robert Israel's suggestion.  Isn't it time that this problem was sorted?

Getting back to Maple, I tried greater than symbols and obtained plots, but with the error message:

Warning, unable to evaluate the functions to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct

What's the reason, please?

J. Tarr

Please see http://en.wikipedia.org/wiki/Specific_heat.

J. Tarr

Jacques,

Thanks for emphasizing my point. One could take it further and say that Maplesoft needs to get a firmer grip on new development, who it's for (many or minority) and is it just bloatware. Maybe you'd like to start a poll on the most useful parts/packages in Maple 11 to give Maplesoft a better idea of what it's customers really want.

J. Tarr

amahmed5

Another way of viewing functions as tables is to use the built-in spreadsheet. Please see ?worksheet,spreadsheet,references. It gives an example that is almost identical to yours.

Spreadsheets in Maple don't seem to get much attention. I suspect that they were once someone's bright idea, but the customers aren't really interested.

J. Tarr

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