## 132 Reputation

16 years, 301 days

## Particular Solution and dsolve...

Maple

Hi there,

I have a de that I have gotten maple to solve using dsolve (y'''+2y''-11y'-12y)=48-28exp(3t). When the solution comes up however, the particular solution is in an odd form:

(-4*exp(3*t)+(11/28)*exp(6*t)-t*exp(6*t))*exp(-3*t)

+_C1*exp(-4*t)+_C2*exp(-t)+_C3*exp(3*t)

However, the particular solution here contains part of the homogeneous solution inside of it: namely the 11/28exp(3t) term. Is there any way to run a function on my solution...

## How do I create a 2-variable piecewise f...

Maple

Hey there,

So I'm trying to throw into Maple for analysis the Cauchy problem:

g := piecewise((t, y) <> (0, 0), 4*t^3*y/(t^4+y^2), (t, y) = (0, 0), 0)

y(0)=0.

Is this possible? I'm investigating Uniqueness/existence on it (even though I know the solution already, given that it's Bernoulli in dt/dy with general solution: y(t)=c^2-sqrt(t^4+c^4)  , c is an element of the reals.

I've done some googling and looking around...

## Precision dropping?...

Maple
I have a function: s^5+3.236067976*s^4+(1.*10^(-10)*I)*s^4+5.236067975*s^3+(7.*10^(-10)*I)*s^3-(3.*10^(-10)*I)*s+5.236067975*s^2+3.236067977*s+1.000000000 and I want to drop those terms in s^4, s^3 and s^2 with magnitude less than for example 10^8. I want those imaginary terms gone so I can see my transfer function with only real coefficients. I don't even know what this would be called... so I wasn't able to search for it.

## Max value of a continuous function on an...

Maple
I'm looking for a simple method of finding the maximum of a continuous function on a specific interval. I've thought about just checking endpoints and critical points on the interval... or discretizing the function on the interval in an array and doing it numerically... Or is there a quicker method I'm missing perhaps? The application is: I've got a complex rational function in the Laplace domain corresponding to an analog filter and I need a way of knowing the 3dB frequency, and to do that I need the max.

## Symboled math in text that won't execute...

Maple
In Advanced Engineering Mathematics there are a lot of math symbols within the text that don't execute. They're not simply an inert math statement, like Int or Diff, but rather the symbolic math used solely as text. How is this done?
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