24.9 Problem. Prove the following "comparison" principle for the heat equation. Suppose that fi, f2 C(R) are bounded with f₁(x) 0 u(x, 0) = f(x), ER and VtVxx, xЄR, t> 0 v(x, 0) = f(x), x ЄR. Prove that either u(x,t) = v(x,t) for all x R and t> 0 or that u(x, t) < v(x, t) for all xER and t> 0.

Linear Algebra: A Modern Introduction
4th Edition
ISBN:9781285463247
Author:David Poole
Publisher:David Poole
Chapter7: Distance And Approximation
Section7.3: Least Squares Approximation
Problem 32EQ
Question
24.9 Problem. Prove the following "comparison" principle for the heat equation. Suppose
that fi, f2 C(R) are bounded with f₁(x) <f2(x) for all x and u and v solve
UtUrx, xER, t>0
u(x, 0) = f(x), ER
and
VtVxx, xЄR, t> 0
v(x, 0) = f(x), x ЄR.
Prove that either u(x,t) = v(x,t) for all x R and t> 0 or that u(x, t) < v(x, t) for all
xER and t> 0.
Transcribed Image Text:24.9 Problem. Prove the following "comparison" principle for the heat equation. Suppose that fi, f2 C(R) are bounded with f₁(x) <f2(x) for all x and u and v solve UtUrx, xER, t>0 u(x, 0) = f(x), ER and VtVxx, xЄR, t> 0 v(x, 0) = f(x), x ЄR. Prove that either u(x,t) = v(x,t) for all x R and t> 0 or that u(x, t) < v(x, t) for all xER and t> 0.
Expert Solution
steps

Step by step

Solved in 2 steps with 1 images

Blurred answer