(i) Given that x = 1 is a critical point of the function f(x) = x² − ³x² + 2x + 1, find all critical points and characterize them. Sketch a graph of the function. Find also the absolute maxmimum when the domain for r is the interval 0≤ x ≤ 4. (ii) Draw a contour plot of the function z(x, y) = x² - y² in the xy-plane, and sketch a graph of this function in the xyz Cartesian frame.

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

could you please provide explanations

(i) Given that x = 1 is a critical point of the function f(x) = x¹ - ³x² + 2x + 1, find all critical
points and characterize them. Sketch a graph of the function. Find also the absolute maxmimum
when the domain for x is the interval 0 ≤ x ≤ 4.
(ii) Draw a contour plot of the function z(x, y) = x² - y² in the xy-plane, and sketch a graph of
this function in the xyz Cartesian frame.
Transcribed Image Text:(i) Given that x = 1 is a critical point of the function f(x) = x¹ - ³x² + 2x + 1, find all critical points and characterize them. Sketch a graph of the function. Find also the absolute maxmimum when the domain for x is the interval 0 ≤ x ≤ 4. (ii) Draw a contour plot of the function z(x, y) = x² - y² in the xy-plane, and sketch a graph of this function in the xyz Cartesian frame.
Expert Solution
Step 1: optimization of given function

(i) Given function is f left parenthesis x right parenthesis equals 1 fourth x to the power of 4 minus 3 over 2 x squared plus 2 x plus 1

Here critical points obtained from f apostrophe left parenthesis x right parenthesis equals 0 rightwards double arrow x cubed minus 3 x plus 2 equals 0

Now given that x equals 1 is a critical point of given function .

s o space f apostrophe left parenthesis 1 right parenthesis equals 0 comma space t h e n space f apostrophe left parenthesis x right parenthesis equals 0 rightwards double arrow x squared open parentheses x minus 1 close parentheses plus x open parentheses x minus 1 close parentheses minus 2 open parentheses x minus 1 close parentheses equals 0rightwards double arrow x equals 1 comma 1 comma negative 2

Now f apostrophe apostrophe open parentheses x close parentheses equals 3 open parentheses x squared minus 1 close parentheses space a n d space f apostrophe apostrophe apostrophe open parentheses x close parentheses equals 6 x space

Here at x equals negative 2 comma f apostrophe apostrophe left parenthesis negative 2 right parenthesis equals 9 greater than 0,so f space h a s space l o c a l space m i n i m u m space v a l u e space a t space x equals negative 2 space.

Now f apostrophe apostrophe left parenthesis 1 right parenthesis equals 0 space,so from here we can not arise any conclusion about local minima/local maxima .

Now f to the power of apostrophe apostrophe apostrophe end exponent open parentheses 1 close parentheses equals 6 not equal to 0, so at x equals 1f has neither local minimum nor local maximum value .

Now noted that f apostrophe open parentheses x close parentheses equals open parentheses x minus 1 close parentheses squared open parentheses x plus 2 close parentheses

when 0 less or equal than x less than 1 space t h e n space f apostrophe left parenthesis x right parenthesis space greater than 0 space a n d space w h e n space 1 less than x less or equal than 4 space t h e n space f apostrophe left parenthesis x right parenthesis greater than 0 

from below graph we have seen that f is non decreasing function on open square brackets 0 comma 4 close square brackets .

so absolute maximum of f on open square brackets 0 comma 4 close square brackets is obtained at x equals 4

which is f left parenthesis 4 right parenthesis equals 64 minus 24 plus 8 plus 1 equals 73 minus 24 equals 49


steps

Step by step

Solved in 6 steps with 28 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,