PDA

View Full Version : maths help!!!

aussie_iron86
08-13-2010, 02:06 AM
hey guys,

i have 2 maths problems that i am struggling with. Does anyone know how to do these two laplace questions

Find laplace of

d^2y/dt^t-13dy/dt+42y=6e^(-4t)
y(0)=0
y'(0)=3

and find the solution of the integral using laplace

f(t)=5+3t^2+2{f(u)sin(2(t-u))

the { is meant to be the integral sign

Thanks

Deathstriker666
08-13-2010, 02:51 AM
No sorry. I would be studying this semester if I wasnt going overseas. I heard its horrible though. Try wolframalpha.com.

TypicalGamer
08-13-2010, 10:28 AM
hey guys,

i have 2 maths problems that i am struggling with. Does anyone know how to do these two laplace questions

Find laplace of

d^2y/dt^t-13dy/dt+42y=6e^(-4t)
y(0)=0
y'(0)=3

and find the solution of the integral using laplace

f(t)=5+3t^2+2{f(u)sin(2(t-u))

the { is meant to be the integral sign

Thanks

If I had a scanner I'd post up the solution. Cbf writing it out on keyboard. Try yahoo answers?

MiscMathematician
08-13-2010, 03:31 PM
you mean y''-13y'+42y=6e^(-4t) I'm assuming? That fractional notation is **** if not in TeX.

First step is to find the homgeneous solution. Though in this case, simple guessing might be easier. Let y=ke^(ct). Its been a while since ide done odes though.