# differential

1. ### First Order Non Linear -getting started

It's been awhile since I've solved a differential equation. The L,D,R,T,M, Re are constants. p(L,t)=(14.7+95t) trying to get a result that shows mass m with respect to time t. m(t)=.....
2. ### Second Order Differential Equation

Y'' + Y = SinX I'm not sure as to what to use as my particular integral, I've tried λsinx and λxsinx which didn't seem to work, I also tried μcosx + βsinx which didn't work either? Could anyone help with which PI to use? Thanks
3. ### Need guidance with deriving expression for differential Maxwell Model

Hi, I require some guidance with this problem below. I'm not sure I understand what to do or what it's asking in the question, where it states "Derive the expression for the differential version" I have attached a PDF document with the Maxwell Model equation, in addition I need to show it by...
4. ### Finding the derivative

Hello. We have an assignment where we have to determine the derivative with respect to x. The problem is f(x)=(sqrt(x+5))/x^2 The answer is We don't know how to get to this answer, if anyone could help out, it would be much appreciated (Happy)
5. ### chemical reaction rate differential equation.

Hi guys, Need some help with this separable differential equation. I understand that I have to use separation of variables and integration by partial fractions (it is a second order reaction rate equation where K is the reaction rate constant). I can get it to this form...
6. ### differential equations and numerical methods questions ??

i have been trying to follow computer oriented numerical methods in c language for some time now ... these were the things i was supposed to do with a programming language like c ... i have managed it this far ... there were at least 5 books i had to follow ..to understand this...
7. ### few more doubts about differential equations ... ?

i have been self learning maths for some time now ... i am out of college ... and this is what i have been doing with my free time ... its sort of sad , that most forums wont allow me to post pictures of maths related stuff ... and deletes it saying its unrelated and spam ... but i have been...

17. ### Writing differential equations

A person receives a drug intravenously at a rate of 3 mg/hr. The drug is eliminated from the body at a rate proportional to the amount present with a constant of proportionality k = -0.4 a) Differential equation for quantity Q of the drug present in the body after t hours This would be dQ/dt =...
18. ### Differential of Laplace transform

I'm taking the Laplace transform of t(y'). The table of transforms says the transform of t^nf(t) is (-1)^nF^n(s). So the transform I want is -d/ds[sY(s)-y(0). I would have thought that derivative would be -Y(s)-o. The class notes say it's -sY'(s)-Y(s). I have no idea why. I don't know if...
19. ### Ordinary differential equations - can't follow integration step

Hi, In my lecture notes is a problem that reads: A radioactive substance decays at a rate proportional to the amount present. If we start with 10gm, how long until only 0.1g remains if the constant of propotionality is k=-1.4^10^-11 sec^-1. The solution says the solution to the ODE dR/dt=kR and...
20. ### Differential Calculus

I wanted to know what is the derivative of signum function And please help to calculate derivative of signum(x^3)