Suppose u is a twice continuously differentiable function with linear growth, <munder> <mo m

Yahir Crane

Yahir Crane

Answered question

2022-06-14

Suppose u is a twice continuously differentiable function with linear growth,
lim x u ( x ) 1 g ( x ) u ( x ) = 0
and g is a Lipschitz continuous function with Lipschitz constant L < 1.
Consider the first order linear homogenous differential equation
y ( x ) 1 g ( x ) y ( x ) = 0 .
The general solution is
y ( x ) = c exp ( 1 g ( x ) d x )
for constant c R . In any solution with linear growth, lim x y ( x ) = 0
Is it possible to conclude that lim x u ( x ) = 0?

Answer & Explanation

kuncwadi17

kuncwadi17

Beginner2022-06-15Added 16 answers

If we only consider the limit
lim x u ( x ) 1 g ( x ) u ( x ) = 0
and impose conditions u C 2 ( R ) , , u ( x ) = O ( x ) , , and g – Lipschitz continuous with L < 1, then the answer is no, we cannot conclude that
lim x u ( x ) = 0.
Counterexample: set u(x)=2x, and g(x)=x. Then all conditions are satisfied,
lim x u ( x ) 1 g ( x ) u ( x ) = lim x ( 2 1 x 2 x ) = 0 ,
and yet
lim x u ( x ) = .

Do you have a similar question?

Recalculate according to your conditions!

New Questions in Differential Equations

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?