3. Find the absolute maximum and minimum values of the function f(x,y)=x-2.xy +2y on the rectangle D = {(x, y)|0

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
This problem is already solved, can you rewrite the problem in clear steps to get the same answer? It’s not completely clear to me. thank you.
(3. Find the absolute maximum and minimum values of the function ƒ(x,y)=x² -2.xy+2y on the rectangle
D= {(x, y)|0<x<3,0< y<2}.
3.
Since fis a polynomial, It is continuous on the closed, bounded rectangle D.
so there is both an absolute maximum and an absolute minimum.
we first find the critical points. These occur when
f, = 2x - 2y= 0
f, = -2x + 2 =0
so the only critical point is (1, 1), and the value of f there is (1, 1) = 1.
we look at the values of F on the boundary of D, which consists of the four
line segments L, L, L, L.
(2,2)
(0, 2)
(3, 2)
L.
(0,0)
(3,0)
On L, we have y=0 and
f(x, 0) = x
This is an increasing function or x. so 1ES minimum value is rtu. 0) = 0 and its maxi-
mum value is F(3, 0) = 9. On Lz we have r= 3 and
(3. y) = 9 - 4y
0 <y 2
This is a decreasing function of y, so its mmaximum value is f(3, 0) = 9 and its minimum
value is f(3, 2) = 1. On La we have y= 2 and
f(x, 2) = x-4x + 4
0 <x3
or simply by observing that f(x, 2) = (x- 2), we see
By the methods of Cal. 1.
that the minimum value of this function is f(2, 2) = 0 and the maximum value is
(0, 2) = 4. Finally, on L we have x= 0 and
r(0. y) = 2y
0 y 2
with maximum value f(0, 2) = 4 and minimIum value N0. 0) = 0. Thus, on the bound-
ary, the minimum value of f is 0 and the maximum is 9.
we compare these values with the value f(1, 1) = 1 at the critical point and
conclude that the absolute maximum value of f on Dis 3, 0) = 9 and the absolute
minimum value is (0, 0) = F(2, 2) = 0. Figure 13 shows the graph of f.
Transcribed Image Text:(3. Find the absolute maximum and minimum values of the function ƒ(x,y)=x² -2.xy+2y on the rectangle D= {(x, y)|0<x<3,0< y<2}. 3. Since fis a polynomial, It is continuous on the closed, bounded rectangle D. so there is both an absolute maximum and an absolute minimum. we first find the critical points. These occur when f, = 2x - 2y= 0 f, = -2x + 2 =0 so the only critical point is (1, 1), and the value of f there is (1, 1) = 1. we look at the values of F on the boundary of D, which consists of the four line segments L, L, L, L. (2,2) (0, 2) (3, 2) L. (0,0) (3,0) On L, we have y=0 and f(x, 0) = x This is an increasing function or x. so 1ES minimum value is rtu. 0) = 0 and its maxi- mum value is F(3, 0) = 9. On Lz we have r= 3 and (3. y) = 9 - 4y 0 <y 2 This is a decreasing function of y, so its mmaximum value is f(3, 0) = 9 and its minimum value is f(3, 2) = 1. On La we have y= 2 and f(x, 2) = x-4x + 4 0 <x3 or simply by observing that f(x, 2) = (x- 2), we see By the methods of Cal. 1. that the minimum value of this function is f(2, 2) = 0 and the maximum value is (0, 2) = 4. Finally, on L we have x= 0 and r(0. y) = 2y 0 y 2 with maximum value f(0, 2) = 4 and minimIum value N0. 0) = 0. Thus, on the bound- ary, the minimum value of f is 0 and the maximum is 9. we compare these values with the value f(1, 1) = 1 at the critical point and conclude that the absolute maximum value of f on Dis 3, 0) = 9 and the absolute minimum value is (0, 0) = F(2, 2) = 0. Figure 13 shows the graph of f.
Expert Solution
steps

Step by step

Solved in 2 steps with 2 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,