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@tomleslie 

One question though:

How is the er term generated?

@mmcdara 

Thanks for the info!  Could you provide an example of a differential equation with initial conditions that are derivatives?

That is what I would like to see.  I don't know how to program that into maple.

 

@Rouben Rostamian  

 

Hi,

The actual form of the antiderivative is wrong, not arbitrariness up to a constant.  If you look at the solution that maple gave me, it is not the same as the equation you have.

 

Can you run my file on your copy of maple and tell me if you get the same thing?

 

If there is nothing wrong with my maple output, how do I know when I can use the integral button in the calculus drop down menu, and when I need to use one of the techniques discussed on this post?

I just tested the integral button, and it by works for integrating x.  The constant C is not included in the output.

@mmcdara 

I_am_getting_different_results_with_maple.mw

I made a maple file where I calculate the antiderivative.  The antiderivative I got from maple is not the same as the antiderivative that you guys got.  Do you guys know what is wrong?

 

 

@Rouben Rostamian  

Interesting.  That is the result I was looking for.  How would you write this out by hand?

@Carl Love 

Hi,

I tried to write Maple code for the following equation:

Numeric_solution_to_this_equation.mw

I got the same error.  I tried the methods on the posts, but still got errors.

What would you recommend?

test_solve.mw

@vv 

I substituted y^2 = x^2 + 1 into helpode_solution2, and the result did not simplify to zero on both sides.  To illustrate what I mean, I did the same thing for a circle.  Use the implicit equation for a circle, solve for y, then insert that back into the implicit equation, and you get zero.

 

I haven't done the second calculation you mentioned yet.  Please see the attached maple file.

Here is the maple file

help_page_ode_investigation.mw

@ 

I have been looking at the code, and it makes sense.  I will look at it again later.  I am still pretty new to maple

 

Steve

Hi,

I have learned about numerical differentiation in my PhD.  I would like to numerically verify the result you created.

 

Is there a way for me to extract a table of (x,y) values for the numerically produced solution, so that I can do numerical first and second derivatives on the solution, numerically substitute the results into the differential equation, and verify the results?

 

Steve

@acer plots:-fieldplot([1, y^2 + x], x = -10 .. 10, y = -6 .. 6, fieldstrength = fixed, color = COLOR(HSV, 0.5*sqrt((y^2 + x)^2 + 1)/((1 + 10) + 36), 1, 1.0))

 

I think I know what you did.  I scaled the colours by 0.5, so that the colour spectrum does not repeat itself.  My next question is "How do I reverse the gradient so that red represents large magnitude, and blue small?"

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