simple differential quesion


by jwqwerty
Tags: differential, quesion, simple
jwqwerty
jwqwerty is offline
#1
Mar18-12, 06:31 AM
P: 23
1. The problem statement, all variables and given/known data

1. ty'+2y = 4t^2 , y(1) = 2


2. Relevant equations



3. The attempt at a solution

1. I know how to get the answer but i have a trivial question. The answer is y=t^2 + t^(-2) and t>0. I do not get why t>0. Why can't t be R except 0?
Phys.Org News Partner Science news on Phys.org
Simplicity is key to co-operative robots
Chemical vapor deposition used to grow atomic layer materials on top of each other
Earliest ancestor of land herbivores discovered
Daniiel
Daniiel is offline
#2
Mar18-12, 08:12 AM
P: 125
I think it can be all the reals except zero, but the fact that both t's are to the power of two cancels any negatives.
So you would really just end up with all the positive reals as any negatives would produce the same solution as positives.
Coto
Coto is offline
#3
Mar18-12, 08:25 AM
P: 308
Agree with Daniiel, you can also consider it from the physical standpoint, that generally t represents time and for modelling purposes we typically restrict [itex]t \geq 0[/itex] to correspond with this notion.


Register to reply

Related Discussions
Differentiation Quesion Calculus 26
Quesion: who is Einstein? History & Humanities 8
Signals & Systems - Quesion Engineering, Comp Sci, & Technology Homework 4
heres a quesion General Engineering 5
Kinetic energy quesion...need help... Introductory Physics Homework 5