Let f be a function of two variables x and y defined on an open region U -(x, y) and dx af (x, y) exist on U. If they are totally differen- ду such that both tiable at a point (a, b) e U, then show that - (а, b) дхду a²f (a,b). дудх This is due to Young (1909) and called the fundamental theorem of differen- tials. Note that no continuity for the partial derivatives are assumed. It is easily verified that xy(x² – y²) x² + y? if (x, y) # (0,0), f(x, y) = if (x, у) %3D (0,0), satisfies a²f -(0,0) = 1. дудх -(0,0) = -1 and дхду Check that this function does not satisfy the conditions stated in the problem.

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question
Let f be a function of two variables x and y defined on an open region U
ôf
OI (x,y) and
dx
tiable at a point (a,b) e U, then show that
such that both
-(x, y) exist on U. If they are totally differen-
ду
-(a, b) =
-(а,).
дхду
дудх
This is due to Young (1909) and called the fundamental theorem of differen-
tials. Note that no continuity for the partial derivatives are assumed.
It is easily verified that
xy(x² – y²)
x² + y2
if (x, y) # (0,0),
f(x, y) =
if (x, y) = (0,0),
satisfies
a²f
²f
-(0,0) = 1.
дудх
-(0,0) = –1 and
дхду
Check that this function does not satisfy the conditions stated in the problem.
Transcribed Image Text:Let f be a function of two variables x and y defined on an open region U ôf OI (x,y) and dx tiable at a point (a,b) e U, then show that such that both -(x, y) exist on U. If they are totally differen- ду -(a, b) = -(а,). дхду дудх This is due to Young (1909) and called the fundamental theorem of differen- tials. Note that no continuity for the partial derivatives are assumed. It is easily verified that xy(x² – y²) x² + y2 if (x, y) # (0,0), f(x, y) = if (x, y) = (0,0), satisfies a²f ²f -(0,0) = 1. дудх -(0,0) = –1 and дхду Check that this function does not satisfy the conditions stated in the problem.
Expert Solution
steps

Step by step

Solved in 5 steps with 5 images

Blurred answer
Recommended textbooks for you
Advanced Engineering Mathematics
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
Numerical Methods for Engineers
Numerical Methods for Engineers
Advanced Math
ISBN:
9780073397924
Author:
Steven C. Chapra Dr., Raymond P. Canale
Publisher:
McGraw-Hill Education
Introductory Mathematics for Engineering Applicat…
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
Mathematics For Machine Technology
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
Basic Technical Mathematics
Basic Technical Mathematics
Advanced Math
ISBN:
9780134437705
Author:
Washington
Publisher:
PEARSON
Topology
Topology
Advanced Math
ISBN:
9780134689517
Author:
Munkres, James R.
Publisher:
Pearson,