Hello,

I have trouble understanding how to go about solving the function g. All that is known is that

1) the function g is a square function

2)

Could someone please help me understand how to solve these kinds of problems?

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- December 9th 2009, 07:23 AMBato91Define g if equation resulting from g(x)+g'(x) is known
Hello,

I have trouble understanding how to go about solving the function g. All that is known is that

1) the function g is a square function

2)

Could someone please help me understand how to solve these kinds of problems? - December 9th 2009, 08:00 AMHallsofIvy
What do you mean by "square function"? My first thought was a "square wave" (beloved of electrical engineers) but I suspect you mean just a "

**quadratic**function. Okay, the most general quadratic function would be for numbers a, b, and c. Then and the equation you have becomes . Combine "like powers" on the left, set the corresponding coefficients equal and solve for a, b, and c. - December 9th 2009, 11:15 AMBato91
Yes I meant a quadratic function!

I don't follow when you write*Combine "like powers" on the left*...

I get how , since there is only one coefficient of . - December 9th 2009, 06:16 PMmr fantastic
- December 9th 2009, 07:22 PMchisigma
Pratically we have a classical first order linear DE...

(1)

... of which we are searching a solution in some sense 'quadratic'. If we proceed in 'standard fashion' we find that...

(2)

... where c is an arbitrary constant. Now may be that for 'quadratic' we intend that it must be ... or may be some else (Thinking) ...

http://digilander.libero.it/luposabatini/notte1.jpg

Merry Christmas from Italy

- December 10th 2009, 04:47 AMHallsofIvy