View Full Version : Existence and Uniqueness


oxymoron
06-12-04, 04:32 AM
I have been doing my calculus revision for my final next week and I am getting stuck on a specific type of question. Here is an example:

Q1)

(300-2t)dM/dt + 4M = 5ln(1000+t), M(0) = 0

An extension of the Existence and Uniqueness Theorem guarantees that the largest interval on which a unique solution exists and is continuous is:
(a) -&infin; < t < &infin;
(b) 0 < t < &infin;
(c) -1000 < t < 150
(d) -1000 < t < &infin;
(e) -&infin; < t < 150

Q2)

For which initial value problem does the Fundamental Existence and Uniqueness Theorem NOT guarantee the existence of a unique solution?

(a) y' = xy^1/2 , y(0) = 1
(b) y' = xy^1/2 , y(1) = 0
(c) y' = yx^1/2 , y(0) = 1
(d) y' = yx^1/2 , y(1) = 0
(e) All of the above

For those interested the answers are C and B respectively.

The question is... could some give me a quick tutorial on the idea of solving these types of problems, or perhaps a personal account on how they solve them or even hints or their own way of looking at them.

darktr00per
06-12-04, 04:37 AM
hmmm... Doesnt look right for some reason.

darktr00per
06-12-04, 04:39 AM
see if this helps http://www.utpb.edu/scimath/wkfield/mod3/Exuni.htm