#### friesepferd

##### New member

- Joined
- Jun 27, 2006

- Messages
- 1

rewrite the given system as a first order system. also indicate what quantities must be specified in an appropriate set of auxiliary conditions for the given system at a point t0

x'1 - x'2 - x1 = cos t

x'2 - 3x1 = e^t

the answer is the following. i just dont know how to get there:

x'1 = 4x1 + cos t + e^t x1(t0)=k1

x'2 = 3x1 +e^t x2(t0)=k2

please help!. my teacher is out of the country and we are suppose to learn this stuff from the book but the book sux and this problem as well as these next two are due real soon!:

x'1 - x'2 = e^t

x''2 - x1 - x2 - x'2 = sin t

and the last problem:

x'''1 - x'1 +x1*x'2 = sin t

x''1 - x2*x'1 - x''2 = cos t

thanks!