Chabot Mathematics
§3.3b 3-Var
System Apps
Bruce Mayer, PE
Licensed Electrical & Mechanical Engineer
BMayer@ChabotCollege.edu
Chabot College Mathematics
1
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Review § 3.3
MTH 55
 Any QUESTIONS About
• §3.3a → 3 Variable Linear Systems
 Any QUESTIONS About HomeWork
• §3.3a → HW-10
Chabot College Mathematics
2
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Equivalent Systems of Eqns

Operations That Produce Equivalent
Systems of Equations
1. Interchange the position of any two eqns
2. Multiply (Scale) any eqn by a nonzero
constant; i.e.; multiply BOTH sides
3. Add a nonzero multiple of one eqn to
another to affect a Replacment
 A special type of Elimination called
Gaussian Elimination uses these steps
to solve multivariable systems
Chabot College Mathematics
3
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Gaussian Elimination
 An algebraic method used to solve
systems in three (or more) variables.
 The original system is transformed to an
equivalent one of the form:
Ax + By + Cz = D
Ey + Fz = G
Hz = K
 The third eqn is solved for z and backsubstitution is used to find y and then x
Chabot College Mathematics
4
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Gaussian Elimination
1. Rearrange, or InterChange, the
equations, if necessary, to obtain the
Largest (in absolute value) x-term
coefficient in the first equation. The
Coefficient of this large x-term is called
the leading-coefficient or pivot-value.
2. By adding appropriate multiples of the
other equations, eliminate any x-terms
from the second and third equations
Chabot College Mathematics
5
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Gaussian Elimination
2. (cont.) Rearrange the resulting two
equations obtain an the Largest (in
absolute value) y-term coefficient in
the second equation.
3. If necessary by adding appropriate
multiple of the third equation from Step
2, eliminate any y-term from the third
equation. Solve the resulting equation
for z.
Chabot College Mathematics
6
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Gaussian Elimination
4. Back-substitute the values of z from
Steps 3 into one of the equations in
Step 3 that contain only y and z, and
solve for y.
5. Back-substitute the values of y and z
from Steps 3 and 4 in any equation
containing x, y, and z, and solve for x
6. Write the solution set (Soln Triple)
7. Check soln in the original equations
Chabot College Mathematics
7
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Gaussian Elim
 Solve System by
Gaussian Elim
1
2
3
6 x  3 y  4 z  41
12 x  5 y  7 z  26
 5 x  2 y  6 z  14
 INTERCHANGE, or
Swap, positions of
Eqns (1) & (2) to get
largest x-coefficient
in the top equation
Chabot College Mathematics
8
1
2
3
12 x  5 y  7 z  26
6 x  3 y  4 z  41
 5 x  2 y  6 z  14
 Next SCALE by
using Eqn (1) as the
PIVOT To Multiply
• (2) by 12/6
• (3) by 12/[−5]
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Gaussian Elim
 The Scaling
Operation
1
12 x  5 y  7 z  26
12
2 6 x  3 y  4 z  41
6
12
 5 x  2 y  6 z  14
3
5
1
2
3
12 x  5 y  7 z  26
12 x  6 y  8 z  82
12 x  4.8 y  14.4 z  33.6
Chabot College Mathematics
9
 Note that the 1st
Coeffiecient in the
Pivot Eqn is Called
the Pivot Value
• The Pivot is used to
SCALE the Eqns
Below it
 Next Apply
REPLACEMENT by
Subtracting Eqs
• (2) – (1)
• (3) – (1)
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Gaussian Elim
 The Replacement
Operation Yields
1
2
3
12 x  5 y  7 z  26
0 x  11y  15 z  108
0 x  9.8 y  7.4 z  7.6
Or
1
2
3
12 x  5 y  7 z
 11y  15 z  108
 9.8 y  7.4 z  7.6
Chabot College Mathematics
10
 26
 Note that the
x-variable has been
ELIMINATED below
the Pivot Row
• Next Eliminate in
the “y” Column
 We can use for the
y-Pivot either of −11
or −9.8
• For the best numerical
accuracy choose the
LARGEST pivot
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Gaussian Elim
 Our Reduced Sys
1
2
3
 11y  15 z  108
1
2
 9.8 y  7.4 z  7.6
3
12 x  5 y  7 z
 26
12 x  5 y  7 z
 26
 11y  15 z  108
 11
 9.8 y  7.4 z  7.6
 9.8
Or
 Since | −11| > | −9.8|
we do NOT need to
1 12 x  5 y  7 z
interchange (2)↔(3)
 Scale by Pivot
against Eqn-(3)
Chabot College Mathematics
11
2
3
 11y  15 z
 26
 108
 11y  8.306 z  8.531
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Gaussian Elim
 Perform
Replacement by
Subtracting (3) – (2)
1
2
3
12 x  5 y  7 z
 11y  15 z
 26
 Find y & x by BACK
SUBSTITUTION
 108
 From Eqn (2)
 23.306 z  116.531
 Now Easily Find
the Value of z from
Eqn (3)
z  116.531 23.306  5
Chabot College Mathematics
12
 The Hard Part is
DONE
108  15 z 108  75
y

 11
 11
y  33  11  3
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Gaussian Elim
 BackSub into (1)
1
2
3
6 x  3 y  4 z  41
12 x  5 y  7 z  26
12 x  5 y  7 z  26
7 z  5 y  26
x
 5 x  2 y  6 z  14
12
35  15  26 24
x

2
12
12
 x=2
 Thus the Solution
Set for Our Linear
System
Chabot College Mathematics
13
 y = −3
 z=5
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Useage Rates
 A food service distributor conducted a
study to predict fuel usage for new delivery
routes, for a particular truck. Use the chart
to find the rates of fuel consumption in rush
hour traffic, city traffic, and on the highway.
Rush Hour
Hours
City Traffic
Hours
Highway
Hours
Total Fuel
Used (gal)
Week 1
2
9
3
15
Week 2
7
8
3
24
Week 3
6
18
6
34
Chabot College Mathematics
14
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Usage Rates
 Familiarize: The Fuel Use Calc’d by
the RATE Eqn:
Quantity = (Rate)·(Time) = (Time)·(Rate)
 In this Case the Rate Eqn
(UseTime)·(UseRate) → (hr)·(Gal/hr)
• So LET:
– x ≡ Fuel Use Rate (Gal/hr) in Rush Hr Traffic
– y ≡ Fuel Use Rate (Gal/hr) in City Traffic
– z ≡ Fuel Use Rate (Gal/hr) in HiWay Traffic
Chabot College Mathematics
15
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Usage Rates
 Translate: Use Data Table
Rush Hour
Gallons
Week 1
2x
Week 2
7x
Week 3
6x
City Traffic
Gallons



9y
8y
18y



Highway
Gallons
3z
3z
6z



Total Fuel
Used (gal)
15
24
34
2 x  9 y  3z  15 1
 Thus the
System of 7 x  8 y  3z  24 2
Equations 6 x  18 y  6 z  34 3
Chabot College Mathematics
16
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Usage Rates
 Solve by Guassian Elimination:
Interchange to place largest
x-Coefficient on top
7x 
8y
 3z  24
2x 
9y
 3z  15
6 x  18 y  6 z  34
2
1
3
 Scale
• Multiply Eqn (1) by −7/2
• Multiply Eqn (2) by −7/6
Chabot College Mathematics
17
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Usage Rates
 The new, equivalent system
8y

3z

24
63
21
105
 7x   y   z  
2
2
2
119
 7 x   21 y   7 z  
3
7x

2
4
5
 Make Replacement by Adding Eqns
• {Eqn (2)} + {Eqn (4)}
• {Eqn (2)} + {Eqn (5)}
Chabot College Mathematics
18
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Usage Rates
 The new, equivalent system
7x 
8y

3z
 24
47
15
57
 
y   z  
2
2
2
47
  13 y   4 z  
3
2
6
7 
 Notice how x has been Eliminated
below the top Eqn
 Clear Fractions by multiplying
Eqn (6) by −2
Chabot College Mathematics
19
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Usage Rates
 The new, equivalent system
7x 

8y
47 y


3z
15 z


24
57
47
  13 y   4 z  
3
2
8
7 
 Now Scale Eqn (7) by the factor 47/13
47 
47  
188
2209 
 13 y  4 z      47 y 
z

13 
3 
13
39 
Chabot College Mathematics
20
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Usage Rates
 The new, equivalent system
7x 

2
8
9
3z

24
15 z

57
188
2209
  47 y  
z  
13
39
8y
47 y


 Replace by Adding: {Eqn (8)}+{Eqn (9)}
7 x  8 y  3z  15
 47 y  15 z  57
7
14


z 
13
39
Chabot College Mathematics
21
2
8
10
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Usage Rates
 Solve Eqn (10) for z
14 
14 13 2 1
2
 13   7
  z    z      z 
39 
39 7 3 1
3
 7  13
 BackSub z = 2/3 into Eqn (8) to find y
2
47 y  15   57  47 y  10  57 
3
47
47 y  57  10  47  y 
 y 1
47
Chabot College Mathematics
22
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Usage Rates
 BackSub z = 2/3 and y = 1 into Eqn (2)
to find x 7 x  81  3 2   24  7 x  8  2  24
3
7 x  24  10  7 x  14  x  2
 Chk x = 2, y = 1 & z = 2/3 in Original Eqns
72 
81
22 
91
62  181
Chabot College Mathematics
23
2
 3   24
3
2
 3   15
3
2
 6   34
3
2
1
3
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Fuel Usage Rates
 Continue Chk of x = 2, y = 1 & z = 2/3
14 
8
 2  24
24  24

9
 2  15 
15  15
4
12  18  4  34
34  34

 State: The Delivery Truck Uses
• 2 Gallons per Hour in Rush Hour traffic
• 1 Gallons per Hour in City traffic
• 2/3 Gallons per Hour in HighWay traffic
Chabot College Mathematics
24
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Theater Concessions
 At a movie theatre, Kara buys one
popcorn, two drinks and 2 candy bars,
all for $12. Jaypearl buys two popcorns,
three drinks, and one candy bar for $17.
Nyusha buys one popcorn, one drink
and three candy bars for $11. Find the
individual cost of one popcorn, one
drink and one candy bar
Chabot College Mathematics
25
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Theater Concessions
 Familiarize: Allow UNITS to guide us to
the Total Cost Equation:


$
 $ 
 $ 
  No. CBars 
$Cost  No. Drinks 
  No. PopCorn 

 Drink 
 CBar 
 PopCorn 
 This Eqn does yield the Total Cost as
required. Thus LET
• c ≡ The UnitCost of Candy Bars
• d ≡ The UnitCost of Soft Drinks
• p ≡ The UnitCost of PopCorn Buckets
Chabot College Mathematics
26
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Theater Concessions
 Translate: Translate the Problem
Description, Cost Eqn, and Variable
Definitions into a 3 Equation System


$
 $ 
 $ 
  No. Drinks 
No. PopCorn 
  No. CBars 
  $Cost
 Drink 
 CBar 
 PopCorn 
p
 2d
2 p  3d
p

Chabot College Mathematics
27
d
 2c  $12

Kara
 $17
Jaypearl
 3c  $11
Nyusha
c
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Theater Concessions
 Solve by Guassian Elim: Interchange to
place largest x-Coefficient on top
2 p  3d

c
 17
p
 2d
 2c  12
p

 3c  11
d
1
2
3
 Scale
• Multiply Eqn (2) by −2
• Multiply Eqn (3) by −2
Chabot College Mathematics
28
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Theater Concessions
 The new, equivalent system
2p

3d

c

17
 2 p   4d
  4c   24
 2 p   2d
  6c   22
1
4
5
 Make Replacement by Adding Eqns
• {Eqn (1)} + {Eqn (4)}
• {Eqn (1)} + {Eqn (5)}
Chabot College Mathematics
29
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Theater Concessions
 The new, equivalent system
2p 
3d

 17
c
 d
  3c   7

  5c   5
d
1
6
7
 p Eliminated below the top Eqn
 Elim d by Adding {Eqn (6)} + {Eqn (7)
2p 

17
 d
  3c 
7

  8c   12
Chabot College Mathematics
30
3d

c
1
6
8
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Theater Concessions
 Solve Eqn (8) for c
 8c  12
8
3
 c   c  $1.50
2
 BackSub c = 3/2 into Eqn (6) to find d
 3  14
d  3c  7  d  3   
2 2
14 9 5
d     d  $2.50
2 2 2
Chabot College Mathematics
31
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Theater Concessions
 BackSub c = 3/2 & d = 5/2 into (1) find p
15 3
5 3
2 p  3      17  2 p    17
2 2
2 2
15 3 34
34 18
 2p   
 2p 

2 2 2
2 2
16
1
 2p 
 8  2 p  8 
2
2
8
p   p  $4.00
2
 The Chk is left for you to do Later
Chabot College Mathematics
32
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Theater Concessions
 A Quick Summary
3
c
2
5
d
2
p4
 State: The Cost for the Movie Theater
Concessions:
• $4.00 for a Tub of PopCorn
• $2.50 for a Soft Drink
• $1.50 for a Candy Bar
Chabot College Mathematics
33
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Missing Term
 In triangle ABC, the measure of angle B
is three times the measure of angle A.
The measure of angle C is 60° greater
than twice the measure of angle A.
Find the measure of each angle.
 Familiarize: Make a
C
sketch and label the
A
B
angles A, B, and C.
Recall that the measures of the angles
in any triangle add to 180°.
Chabot College Mathematics
34
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Missing Term
 Translate: This geometric fact about
triangles provides
A + B + C = 180.
one equation:
 Translate Relationship Statements
Angle B is three times the measure of angle A.
B
=
Chabot College Mathematics
35
3A
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Missing Term
 Translate Relationship Statements
Angle C is 60o greater than twice the measure of A
C
=
 Translation
Produces the
3-Equation
System
Chabot College Mathematics
36
60 + 2A
A  B  C  180
B  3A
C  60  2 A
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Missing Term
 Since this System has
A

B

C

180
Missing Terms in two
B  3A
of the Equations,
Substitution is faster
C  60  2 A
than Elimination
 Sub into Top Eqn A  3A  60  2 A  180
• B = 3A
• C = 60+2A
Chabot College Mathematics
37
60  6 A  180
6 A  120
A  20
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Missing Term
 BackSub A = 20° into the other eqns
B  3A
 3(20)
 60
C  60  2 A
 60  2(20)
 100
 Check → 20° + 60° + 100° = 180° 
 State: The angles in the triangle
measure 20°, 60°, and 100°
Chabot College Mathematics
38
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  Missing Term
 In triangle ABC, the measure of angle B
is three times the measure of angle A.
The measure of angle C is 60° greater
than twice the measure of angle A.
Chabot College Mathematics
39
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  CAT Scan
 Let A, B, and C
be three grid
cells as shown
 A CAT scanner
reports the
data on the
following slide
for a patient
named Satveer
Chabot College Mathematics
40
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  CAT Scan

Linear Attenuation Units For the Scan
i.
Beam 1 is weakened by 0.80 units as it
passes through grid cells A and B.
ii. Beam 2 is weakened by 0.55 units as it
passes through grid cells A and C.
iii. Beam 3 is weakened by 0.65 units as it
passes through grid cells B and C

Using the following table, determine
which grid cells contain each of the
type of tissue listed
Chabot College Mathematics
41
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  CAT Scan
 CAT Scan Tissue-Type Ranges
LAU  Linear Attenuation Units
Chabot College Mathematics
42
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  CAT Scan
 Familiarize: Suppose grid cell A
weakens the beam by x units, grid cell B
weakens the beam by y units, and grid
cell C weakens the beam by z units.
 Thus LET:
• x ≡ The Cell-A Attenuation
• y ≡ The Cell-B Attenuation
• z ≡ The Cell-C Attenuation
Chabot College Mathematics
43
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  CAT Scan

Translate: the Attenuation Data
i.
Beam 1 is weakened by 0.80 units as it
passes through grid cells A and B.
x + y = 0.80
ii. Beam 2 is weakened by 0.55 units as it
passes through grid cells A and C
x + z = 0.55
iii. Beam 3 is weakened by 0.65 units as it
passes through grid cells B and C
+ z = 0.65
Chabot College Mathematics
44
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  CAT Scan
 Thus the
Equation
System
 0.80
x  y

 z  0.55
x

y  z  0.65

(1)
(2)
(3)
 Even with Missing Terms Elimination is
sometimes a good solution method
x  y
 0.80
 Add −1 times
Equation (1)
x
 z  0.55
(2)
to Equation (2)
y  z  0.25
(4)
Chabot College Mathematics
45
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  CAT Scan
 0.80 (1)
 The Replacement  x  y

Operation Produces  y  z  0.25 (4)
the Equivalent System

y  z  0.65 (3)

 Add Equation (4) to Equation (3) to get
 0.80 (1)
x  y

 y  z  0.25 (4)

2z  0.40 (5)

Chabot College Mathematics
46
0.40
 z
2
Or z  0.20
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  CAT Scan
 Back-substitute
z = 0.20 into
Eqn (4) to Obtain
 Back-substitute
y = 0.45 into
Eqn (1) and
solve for x
Chabot College Mathematics
47
y  0.20  0.25
y  0.45
y  0.45
x  y  0.80
x  0.45  0.80
x  0.35
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Example  CAT Scan
 Summarizing
Results
 Recall
Tissue-Type
Table
x  0.35 y  0.45 z  0.20
 Thus Conclude
• Cell A contains tumorous tissue (x = 0.35)
• Cell B contains a bone (y = 0.45)
• Cell C contains healthy tissue (z = 0.20)
Chabot College Mathematics
48
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
WhiteBoard Work
 Problems From §3.3 Exercise Set
• 46

An
Inconsistent
System
WHY?
Chabot College Mathematics
49
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
All Done for Today
Carl
Friedrich
Gauss
Chabot College Mathematics
50
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt
Chabot Mathematics
Appendix
r  s  r  s r  s 
2
2
Bruce Mayer, PE
Licensed Electrical & Mechanical Engineer
BMayer@ChabotCollege.edu
–
Chabot College Mathematics
51
Bruce Mayer, PE
BMayer@ChabotCollege.edu • MTH55_Lec-14_sec_3-3a_3Var_Sys_Apps.ppt