Differential Equations/Expert Profile

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• Knowledgeability 9.77
• Clarity of Response 9.90
• Timeliness 9.94
• Politeness 9.97

• Number of Questions (in Past 24 Hours) 0
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• Total Questions (since joining AllExperts) 138
• Volunteer Since 2003-04-30
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    K = Knowledgeability    C = Clarity of Response    T = Timeliness    P = Politeness

User	Date	K	C	T	P	Comments
Grisel	07/26/09	10	10	10	10	Thanks!! that was very helpful
Warm	07/11/09	10	10	10	10	Thanks
Dan	01/14/09	10	10	10	10
Ambika	07/23/08	10	10	10	10	Thanks for your answer.
Cheryl	07/10/08	10	10	10	10	I feel dumb. For some reason .....

Recent Answers from Abe Mantell

2009-07-15 Simultaneous differential equations:

Hello Debraj, Sorry for my delay. I tried to get my CAS (computer algebra system), Maple 12, to solve your system of DE's...but it failed. Perhaps if you could furnish some actual values for the

2009-07-10 Differential equation:

dV/dt=20-k*h^2, based on the info given in the problem. However, V=(4/3)h^3, thus, dV/dt=4*h^2*dh/dt. Now substitute that into the first equation to get: 4*h^2*dh/dt=20-k*h^2. Dividing by 4*h^2 yields:

2009-06-06 Differential Equation, Solutions:

1. Re-written as: y'' + (x^2-1)/(x^2(x+1)) y' - y/(x^2(x+1)) = 0 . Singular points where x^2(x+1)=0...thus x=0 and x=-1 are singular pts. . Since lim (as x->0) x[(x^2-1)/(x^2(x+1))] DNE, x=0 is an

2009-05-31 Maths2:

Let y=e^(rx), so we get the characteristic equation: r^2-4r+4=0 ==> (r-2)(r-2)=0 ==> r=2,2 Repeated root, so the general solution is: y(x)=(A+Bx)e^(2x) Now impose the IC's: y(0)=0 ==> 0=(A+0)e^0

2009-01-05 integrate eq:

Hello, Wow, that's a tough one! Let me just make sure, the problem is: Integrate[dx/(e^(-k1*x)+k2*x+k3)] - yes? If so, then I'm afraid I cannot help, even Maple 12 and Mathematica could not