MATH151, Spring 2003
On this page we will
 - keep track of what we do in class
 - list homework assignments
 - place links to relevant
web pages

e-mail rossa@xavier.xu.edu

WEEK 7

T 2-25

Return Test 1
Continue discussion of Section 9.1
Cross Sectional Models:
     from data // from formula
(Examples: MO Farmland and Wind Chill)
Then we discussed Exercise 14, 20

Missouri Farmland

Homework:
From last time: Sec. 9.1#11,14,19,20
Now also: #7,9,16,23
Prepare (read) Section 9.2.: "Contour Graphs"

R 2-27

Discuss Homework Sec. 9.1
Section 9.2: "Contour Graphs"
 - what is a contour line?
 - how do we find contour lines from
    - data
    - formula
"Reading" a Contour Graph

Contours for
Mis
souri
Farmland

Homework: Sec.9.2.#3,7,13,14,15


WEEK 8

T 3-4

Spring Break

R 3-6

Spring Break

WEEK 9

T 3-11

Review Contour lines:
       Missouri Farmland (see link)
- discuss #15 and #7 or 13 of Sec. 9.2
- contour maps for different contexts
   "reading"/"interpreting" contour maps
- matching contour maps and surfaces

HW: Sec. 9.2 # 16,17,18,19,20,23,24 $ finish hand-outs

No class on Thursday (Rossa out of town)

Settle remaining questions about Sec. 9.1, 9.2 in Math Lab

Prepare (i.e. read and think about) Sec. 9.3

R 3-13

No Class

WEEK 10

T 3-18

Section 9.3.: Partial Derivatives
slope of a surface in x-direction (at a point)
slope of a surface in y-direction (at a point)
 - How to estimate it from contour map of surface
 - How to calculate it from formula for surface
    (Example: Missouri Farmland)

HW: Calculate the slope of the Missouri
Farmland in x-direction at the points
(.5,.5),(.5,1),(1,.5) and (1,1).
Then calculate the slope in y-direction
at these points. Use the method from class.

R 3-20

Section 9.3.: Partial derivatives

A detailed discussion using the Mom and Pop store
example...

Mom 'n Pop
store

HW: Sec. 9.3 # 7,9,10,11,15,17ab,19,24

WEEK 11

T 3-25

Section 9.3.
Discussion of several HW problems
review for test

By popular demand: Test 2 is moved to next Tuesday

HW: Take a look at "second partial derivatives"
in section 9.3.

Read section 10.1: Multivariable Critical Points

R 3-27

Review Optimization for functions of one variable
(MATH150, Chapter five)
Terminology (local/absolute max/min, saddle, critical
point) and connections:
How can we tell that/if we have a loc. max, loc. min,
or saddle at a critical point ... ?
 - check if derivative changes sign
 - via concavity (2nd derivative)

Intro to optimization of functions with two inputs
Terminology (how do we characterize a loc max., ...)
 - What do these things look like in a contour map?
 - finding local extrema and saddle points in a map.
How to locate potential local extrema from the
formula for the surface f(x,y)... ?
 - slope in all directions must = zero, so, in particular,
   both partial derivatives must equal zero ...
   (Example: Missouri Farmland)

Sec. 10.1.:#2,5,7,13,17,18

Take a look ahead at section 10.2.

WEEK 12

T 4-1

Test 2 (Sections 9.1-9.3)

R 4-3

The role of critical points in optimizing functions of
two (or more) variables.
Finding critical points: Theory and practice
 - Missouri Farmland
 - Removing peptides from crayfish processing byproducts (#16)

HW: # 13, 15, 17: Find all critical points

WEEK 13
  e-mail rossa@xavier.xu.edu 

T 4-8

determining if we have
local max. / local min. / saddle point
at critical point.

The D test.

a function which is
concave down in x and
y direction at a critical
point, but does not have
a local maximum...

HW: finish # 13,15,17 in Section 10.2

hand in: #10 of Sec. 10.2 (in new text!)

Begin to read Section 10.3.

R 4-10

Sec. 10.3: Optimizing under Constraints

 - paths through the Missouri Farmland
   (and checking for high and low points
     along the path...)

 - the matress production example...
   optimize under constraint by
   (1) "follow your nose" trial and error
   (2) Substituting K=98-8L into
         productivity formula... (see Cobb
         Dougl. html on right for summary)

Cobb-Douglas
Example (html)

Cobb-Douglas
Example (mws)

HW: Maximize productivity under our
constraint using Math150 methods on
P = 48.1 . L0.6 . K1-0.6 after substituting
the constraint K + 8L = 98.

also Sec. 10.3. #1,3

WEEK 14

T 4-15

Sec. 10.3: Optimizing under Constraints
Finish (2) from above

The Lagrange Multiplier Method:
The rationale (why it works) and an
example...

HW Sec. 10.3 # 9, 11 I recommend to use both methods:
     (1) use constraint to eliminate one of the variables
     (2) Lagrange multiplier method

Also: optimize the function h(w,z) = .6w2 + 1.3z3 - 4.7wz under
the constraint that z = .6w - 4 and that z must be between 2 and 6.

R 4-17

Easter Holiday -- No Class

WEEK 15

T 4-22

Discussion of Section 10.3 homework
open floor for general questions (chapter 10)

In preparation for the test, I recommend to work the exercises
through #4b of the review test in our text. (not: #4c,d, #5)

R 4-24

Test 3 (chapter 10)

WEEK 16

T 4-29

student presentations

R 5-1

student presentations

Final Exam: Tuesday, May 6th, 4:00-6:00 p.m.