Differential Equations/Experts

Recent Answers

2009-10-31 differential calculas:

Then it was (4-5x²)^(4/3). This is (f(x))^(4/3) where f(x) = 4-5x². The derivative is (4/3)•(f(x))^(1/3)•f'(x), and f'(x) = -10x. Putting the f'(x) out front and multipling th -10 by 4 gives us (-40/3)x•f'(x)•f(x)^(1/3)

2009-10-08 probability:

This sounds like an exponential distribution with L=1/4 where L is for lambda. Since the distribution is f(x) = Le^(-Lx), the cumulative distribution is 1 - e^(-Lt) for x being between 0 and t.

2009-10-06 Ordinary Differential Equation:

This is a standard question and can be solved directly by applying the formulae. No special skills are needed to answer this question. I will just give you some clues and you need to work out the details

2009-10-06 Ordinary Differential Equation:

The equation is y" - 8y' + 18y = 4e^(4x) + 3x^3. The simplest solution that can be found would be y = Ae^(4x) + Bx³ + Cx² + Dx + C. This leads to y' = 4Ae^(4x) + 3Bx² + 2Cx + D. We then get y" = 16Ae^(4x)

2009-10-06 ordinary differential equations:

Again, I' not quite sure this is right, but here goes. You can look at it and tell me what you think. If you get a better way to do it, let me know. Let L be litres and G be grams. The amount of