Download Homework Assignments – Math 122

Homework Assignments – Math 122-01/02 – Spring 2013
Assignment 1
Due date : Friday, January 25
Section 5.1, Page 159: #1-4, 10, 11, 14;
Section 5.2, Page 163: Find slope, y -intercept, and then plot the
line in problems: #2, 4;
Equivalent 5th Edition Set
Section 4.2, Page 132:
#1-4, 10, 11, 14; Find slope, y -
intercept, and then plot the line in
problems: #26, 28;
Find vertex, axis of symmetry, focus,
focal width, and then plot the
parabola in: #30, 32;
Find vertex, axis of symmetry, focus, focal
width, and then plot the parabola in:
#6, 8;
Section 4.1, Page 143: #2, 3, 7, 8,
Section 4.2, Page 151: #3, 4, 6, 13, 14, 15,
29, 30, 32, 34;
Additional Exercises
Section 4.5, Page 146:
#2, 3, 7, 8, 11, 12, 14, 21, 22,
23, 38, 39, 41, 42;
#1 – 4 (below).
Instructions
In problems 1-3, plot the function and indicate its domain and range.
1. f ( x ) =
⎧⎪ x if 0 ≤ x < 2
⎨
⎪⎩1 + x if 2 ≤ x ≤ 5
⎧ 1
if 0 < x < 2
⎪⎪ x
⎨
2
⎪3 - x if 2 ≤ x ≤ 5
⎪⎩ 4
2. f ( x ) =
3. f ( x ) =
| x|
for all x ≠ 0 .
x
4. Determine the value of f [ f ( x ) ] for the function f in problem 3 above.
Assignment 2
Equivalent 5th Edition Set
Due date : Friday, February 1
Section 23.1, Page 745: #2, 3, 7, 8, 9,14, 15, 17, 18, 23, 25, 26,
38.
Additional Exercises #1 – 4 (below).
Section 21.1, Page 617:
#2, 3, 7, 8, 10, 11, 13, 14, 19,
21, 22, 25, 38.
⎧1 − x if x ≤ 0 .
1. (a) Sketch a graph of the function: f ( x ) = ⎨
if x > 0
⎩1
(b) Use the graph from part (a) to state the value of each of the following limits, if it exists.
(i)
(ii)
lim f ( x)
x →0 −
(iii)
lim f ( x)
x →0 +
2. (a) Sketch a graph of the function:
lim f ( x)
x→0
⎧ 2 − x if x < −1
⎪
if − 1 ≤ x < 1
f(x)= ⎪x
⎨
⎪ 4 if x = 1
⎪⎩ 4 − x if x > 1
.
(b) Use the graph from part (a) to state the value of each of the following limits, if it exists.
(i)
lim f ( x)
(ii)
x → −1−
(iii)
lim f ( x)
x → −1+
lim f ( x)
x→ −1
3. A graph of the function y = g ( x ) is shown in the figure.
(a) State the domain and range of g .
(b) Use the graph to determine each of the limits:
( i ) lim g ( x)
+
x → −1
(iv) lim g ( x)
−
x→ 0
(ii)
lim g ( x)
x → − 1−
(iii) lim g ( x)
(v) lim g ( x)
+
x→ 0
x→ − 1
(vi) lim g ( x) .
x→ 0
4. (a) Write a piecewise definition for the function y = g ( x )
shown in the figure.
(b) State the domain and range of g .
(c) Determine the limits: lim g ( x) , lim g ( x) .
−
+
x→ 1
x→ 1
(iv)
lim f ( x)
x→ 1−
(v)
lim f ( x)
x→ 1+
(vi) lim f ( x)
x→ 1
Equivalent 5th Edition Set
Assignment 3
Section 21.3, Page 629:
Due date : Friday, February 8
Section 23.3, Page 758:
Use the method of Example 14, Page 751, to find the derivative
of y = f ( x ) in each of the following problems:
#1, 6, 8, 9, 11, 12.
______________________________________________________________________________
To find the slope of the graph of y = f ( x ) at the given value,
f ( a + Δx ) − f ( a )
x = a, evaluate the limit: dy
= f ′( a ) = lim
Δx→0
dx x=a
Δx
in each of the following problems:
#13, 15, 17, 19.
______________________________________________________________________________
Additional Exercises
Use the method of Example 13, Page
623, to
find the derivative of y = f ( x ) in
each of the following problems:
#1, 6, 8, 9, 11, 12.
______________________________________
To find the slope of the graph of
y = f ( x ) at the given value, x = a,
evaluate the limit:
dy
f ( a + Δx ) − f ( a )
= f ′( a ) = lim
Δx→0
dx x=a
Δx
in each of the following problems:
#13, 15, 17, 19.
#1 – 7 (below).
Instructions
In problems 1-4, estimate the slope of the curve at the point P.
1.
2.
3.
4.
5. Assign one of the following
descriptors to each point
A, B, C, D, E, F in the figure:
•
large positive slope
•
small positive slope
•
zero slope
•
small negative slope
•
large negative slope.
6. Estimate the value of f’(1) in the figure below.
7. Find the equation of the tangent line to f(x) at the
point P.
Assignment 4
Due date : Friday, February 15
Exercises #1 – 10 (below).
Instructions
In problems 1-6, determine whether the given functions is:
(a) continuous at x = 1 ⇔ lim f ( x ) = f (1) .
x→1
(b) differentiable at x = 1 ⇔
f is continuous at x =1 and
lim
Δx → 0 +
f ( 1 + Δx ) − f ( 1 )
Δx
≡
f +′ ( 1 ) =
f −′ ( 1 )
≡
lim
f ( 1 + Δx ) − f ( 1 )
Δx → 0 −
Δx
.
(c) Then sketch a graph of y = f ( x ).
1. f ( x ) = ⎧ x
⎨
⎩2
if x ≠ 1
if
x =1
2
4. f ( x ) = ⎧⎪ 1 - x if − 1 ≤ x < 1
⎨
⎪⎩ x − 1 if 1 ≤ x ≤ 3
2. f ( x ) = ⎧ 2 x − 1 if 0 ≤ x ≤ 1
⎨
if
x >1
⎩1
3
if − 1 ≤ x < 1
5. f ( x ) = ⎧⎪ x
⎨
⎪⎩ 3x − 2 if 1 ≤ x ≤ 3
3. f ( x ) = ⎧ x + 2 if − 1 ≤ x ≤ 1
⎨
if 1 < x ≤ 3
⎩ 3x
⎧ 1
if x ≠ 1
6. f ( x ) = ⎪
⎨ x −1
⎪⎩ 0
if x = 1
In problems 7 and 8, f is defined for all x except for one value. If possible, define f (x) at that exceptional
point in order to make it continuous there.
2
7. f ( x ) = x + x − 12 , x ≠ –4
x+4
2
8. f ( x ) = (6 + x) − 36 , x
≠0
x
2
9. For what number a will the function f ( x ) = ⎧⎪ ( x − a ) + a if x ≤ 1
⎨
if x > 1
⎩⎪ a
be both continuous and
differentiable at x = 1 ? Sketch the graph of y = f ( x ) using this particular value of a.
10. Explain in words why the function described in each case below is either continuous everywhere on its
domain, or if instead, it possesses points of discontinuity. Then sketch a rough graph of the function.
(a) The temperature, T, (as a function of time) of a pitcher of ice water left to stand on a table for
several hours in a 70o F room.
(b) The cost, C, (as a function of time) for parking at the Millennium Park Garage, 5 S. Columbus Drive, in
downtown Chicago for anywhere from 0 to 24 hours. The current 2013 parking rates are:
$23 for 0 to 3 hours
$26 for 3 to 8 hours
$28 for 8 to 12 hours
$30 for 12 to 24 hours.
Assignment 5
Due date : Wednesday, February 27
Section 23.4, Page 764: #1, 2, 8, 12, 13, 18, 20, 22, 28, 35,
46, 49, 61.
Section 23.5, Page 769: #2, 9, 13, 17, 20, 31.
Section 23.6, Page 775: #2, 13, 14, 17, 21, 25, 30, 31, 33,
37, 38, 43.
Equivalent 5th Edition Set
Section 21.4, Page 635:
#1, 2, 8, 12, 13, 18, 20, 22, 28,
35, 46, 49, 61.
Section 21.5, Page 640:
#2, 9, 13, 17, 20, 31.
Section 21.6, Page 645:
#2, 13, 14, 17, 21, 25, 30, 31,
33, 37, 38, 43.
Exam 1 Review Problem Set : (http://mypages.iit.edu/~maslanka/Math122Rvw1.pdf )
. . . . . . . . . . Date for Midterm Exam 1 . . . . . . . Friday, March 1st
...........
Assignment 6
Due date : Friday, March 8
Section 23.7 Page 782: #15, 16, 20, 21, 23, 24, 25,
26, 27, 28, 39.
Additional Exercises
Equivalent 5th Edition Set
Section 21.7 Page 651:
#15, 16, 20, 21, 23, 24, 25,
26, 27, 28, 39.
# 1 – 15 below.
Instructions
Find the derivative of y in each case.
1. y = ( 2 x − 7 )
3
2
2. y = (3 x + 1)
2
2 3
4. y = (3 + x ) (1 − x )
4
3. y = 3 x ( 4 − 9 x )
2 23
5. y = (9 − x )
4
3 − 2x
6. y =
3
7. y =
3
2
9x + 2x + 7
2
x − 2x + 1
8. y =
9.
y=
2x − 1
x
10. y =
x +1
11. y =
x −1
⎞
⎛
13. y = ⎜⎜ x2 + 1 ⎟⎟
x⎠
⎝
4
6x − 5
12. y =
2
x +1
2
14. y = x ( x − 1)
Assignment 7
5
15. y =
2
2x + 3
2
3x − 2 x
( 4 x − 1)
3
2
2x + 1
Equivalent 5th Edition Set
Due date : Monday, March 25
Section 25.4 Page 835: #6, 8, 10, 13.
Additional Exercises
# 1 – 16 below.
Section 23.4 Page 701:
#6, 8, 10, 13.
Refer to the lecture notes (http://mypages.iit.edu/~maslanka/ExtremeValues.pdf)
for details on relative and absolute extreme values and associated theorems and results.
On Relative and Absolute Extreme Values and Critical Numbers
1. Explain the difference between an absolute minimum and a relative minimum value.
2. Suppose that f is a continuous function defined on the closed interval [a , b].
(a) What theorem guarantees the existence of an absolute maximum value and an
absolute minimum value for f ?
(b) What steps would you take to find those absolute extreme values?
In problem 3 – 5, sketch the graph of a function f that is continuous on [1, 5] and has the
given properties.
3. Absolute minimum at 2, absolute maximum at 3, relative minimum at 4.
4. Absolute maximum at 5, absolute minimum at 2, relative maximum at 3, relative
minima at 2 and 4.
5. f has no relative maximum or minimum but 2 and 4 are critical numbers.
Recall that c is a critical number for f ⇔ c is in the interior of dom( f )
and either f ’ (c)= 0 or f ’ (c) does not exist.
6. (a) Sketch the graph of a function that has a relative maximum at 2 and is
differentiable at 2.
(b) Sketch the graph of a function that has a relative maximum at 2 and is
continuous but not differentiable at 2.
(c) Sketch the graph of a function that has a relative maximum at 2 and is
not continuous at 2.
In problems 7 – 10 sketch the graph of f over the indicated interval. Then locate
all absolute and relative maximum and minimum values of f that exist.
7. f (x) = 8 – 3 x , x > 1
8. f (x) = x2 , –1 < x < 2
9. f (x) = x , –1 < x < 2
10. f (x) = 1/x , 0 < x < 2
2
In problems 11 – 16 find all critical numbers for the function, all the intervals on which
f is increasing or decreasing, and all relative and absolute extreme values. Then use this
information to help you sketch a graph of y = f (x).
11. f (x ) = x4 – 2 x2 + 1
12. f (x) = x4 – 2 x3
13. f ( x ) = x + 3 x – 24 x
14. f (x) = | 2x + 3 |
15. f (x) = x – 3 x + 1
16. f (x) =
3
3
2
3
x
⋅ (8 – x)
Assignment 8
Equivalent 5th Edition Set
Due date : Friday, April 5
Section 25.4 Page 836: #17, 21, 23, 29.
Section 29.1 Page 947: #2, 3, 4, 7, 11, 12,
19, 26, 29, 36.
Additional Exercises # 1 – 6 below.
Section 23.4 Page 702:
#17, 21, 23, 29.
Section 27.1 Page 811:
#2, 3, 4, 7, 11, 12, 19, 26, 29, 36.
In problems 1 – 6 find all extreme points and all inflection points for the graph of the
function. Then find all the intervals on which f is increasing, decreasing, concave up,
and concave down and sketch a graph of y = f (x).
(Note that problems 1 – 5 were initially examined in the previous assignment.)
1. f (x ) = x4 – 2 x2 + 1
2. f (x) = x4 – 2 x3
3. f ( x ) = x + 3 x – 24 x
4. f (x) = x3 – 3 x + 1
3
5. f (x) =
3
2
x (8 – x)
6. f (x) = 2 x
1/3
+ x
2/3
Exam 2 Review Problem Set : (http://mypages.iit.edu/~maslanka/Math122Rvw2.pdf )
Exam 2 Review Topics : (http://mypages.iit.edu/~maslanka/Math122E2Tpcs.pdf )
. . . . . . . . . . . Date for Midterm Exam 2 . . . . . . . Wednesday, April 10th . . . . . . . . . . . .
Assignment 9
Equivalent 5th Edition Set
Due date : Wednesday, April 17
Section 29.2 Page 951: #1, 4, 9, 12, 13, 21, 26, 27. Section 27.2 Page 815:
#1, 4, 9, 12, 13, 21, 26, 27.
Additional Exercises # 1 – 3 below.
In problems 1 – 3 do the following:
(a)
Sketch a rectangular plot of the equation in the θr – plane over the indicated θ interval.
(b) Sketch a polar graph of the equation in the xy – plane, where x = r cos θ, y=r sin θ.
(c)
Find the slope to the polar curve at the point ( x, y ) = ( r cos(
by using the formula:
1. r = 2 cos θ ; 0 < θ < π
dy dθ
dy
=
dx
dx dθ
.
2. r = 1 + sin θ ; 0 < θ < 2π
3. r = 2 sin( 3 θ ) ; 0 < θ < π
Equivalent 5th Edition Set
Assignment 10
Due date : Wednesday, April 24
Section 26.1 Page 850: #3, 7, 12, 19, 22, 27, 31,
35, 36, 38, 39.
Section 26.2 Page 857: #1, 3, 6, 7, 8, 10, 17, 20,
21, 24.
Section 26.3 Page 862: #2, 3, 8, 13, 14,17.
Section 29.7 Page 973: #1, 2, 9, 10, 23, 24.
Additional Exercises
π
π
), r sin( ) )
4
4
# 1 – 3 below.
Section 24.1 Page 717:
#3, 7, 12, 19, 22, 27, 31, 35,
36, 38, 39.
Section 24.2 Page 725:
#1, 3, 6, 7, 8,10,17, 20, 21, 24.
Section 24.3 Page 729:
#2, 3, 8, 13, 14,17.
Section 27.7 Page 837:
#1, 2, 9, 10, 23, 24.
In problems 1 – 3 the graph of a function f is displayed. Sketch the graphs of two antiderivative
functions, F1 and F2 , in each case. Include an analysis of the intervals on which F1 and F2 are
increasing/decreasing and concave up/down based on your knowledge of f = Fi’ .
1.
2.
3.
Assignment 11
Due date : Wednesday, May 1
Section 26.4 Page 866: #2, 5, 6, 9, 11, 12, 13.
Section 26.6 Page 874: # 1, 6, 13.
Section 29.7 Page 974: # 27, 29.
Additional Exercises # 1 – 7 below.
Equivalent 5th Edition Set
Section 24.4 Page 733:
#2, 5, 6, 9, 11, 12, 13.
Section 24.6 Page 741: # 1,6,13.
Section 27.7 Page 838: # 27, 29.
1. A uniform horizontal beam of length L having a simple point support at its left end
and a fixed support at its right end will be distorted, due to its own weight, into a curve:
y = f (x) as shown in the figure below .
O
L
x
y
This curve is called the deflection curve of the beam and it satisfies the differential
4
equation: E ⋅ I d y = w along with the four boundary conditions:
dx 4
y ( 0 ) = 0, y ’’( 0 ) = 0
y ( L ) = 0, y ’( L ) = 0
By substituting each boundary condition into either equation (2), (3) or (4) from
page 2 of the article: http://mypages.iit.edu/~maslanka/BeamDeflection.pdf
and then solving for the coefficients, C i , i = 1, 2, 3, 4, verify that the beam’s equation is:
w
[ 2 x 4 − 3Lx 3 + L3 x ]
48EI
___________________
y =
_______
___________
Mean Value Theorem:
If F is continuous on the closed interval [a, b] and differentiable on the open interval
(a, b) then there must exist at least one number c in (a, b) for which
F ’ (c) =
F(b) − F(a)
b−a
In problems 2 and 3 do the following:
(a) Apply the Mean Value Theorem to the function:
3
F (x) = x – 3x
on the indicated interval I to find all numbers, c, in the interior of I , which satisfy
the conclusion of this theorem. I.e., find all numbers c interior to I for which the
average change in F over I is equal to the instantaneous rate of change in F at c.
y = F (x) on the interval I and interpret your results
from part (a) geometrically in terms of the appropriate tangent and secant lines to
your graphs.
(b) Sketch a graph of the function
2. I = [ 0 , +2 ]
3. I = [ –1 , +1 ]
In problems 4 – 7 use the definite integral to find the area of the shaded region in each case.
4.
5.
6.
7.
Assignment 12
Due date : (These problems will not be collected.)
Exercises # 1 – 3 below.
Average Value of a Function:
The average value of the continuous function f on the closed interval [a, b] is:
avg ( f ) =
1
b−a
b
∫ f ( x) dx .
a
1. The surface of a water wave is described by
y = 5 ( 1 + cos x ), for -π < x < π , where
y = 0 corresponds to a trough of the wave.
Find the average height of the water above
the trough on [- π , π ] .
2. The Gateway Arch in St. Louis is 630
feet high and has a 630 foot base. Its
shape can be modeled by the
parabola:
2
⎡
⎛ x ⎞
y = 630 ⎢1 − ⎜
⎟
⎝ 315 ⎠
⎢⎣
⎤
⎥ .
⎥⎦
Find the average height of the arch
above the ground.
3. A hiking trail has an elevation given by
f ( x ) = 60 x 3 − 650 x 2 + 1200 x + 4500
where f is measured in feet above sea
level and x represents horizontal
distance along the trail in miles, with
0 < x < 5.
What is the average elevation of the trail?
Exam 3 Review Problem Set : (http://mypages.iit.edu/~maslanka/Math122Rvw3.pdf )
Extra-Credit Assignment 13
Due at Final Exam: Math 122-01 exam from 8 – 10 am, Monday, May 6
Math 122-02 exam from 2 – 4 pm, Friday, May 10.
Exercises# 1 – 6 On Areas in Polar Coordinates .
Area Theorem: If α and β are angles that satisfy the condition:
α < β < α + 2 π and if f ( θ ) is continuous and nonnegative
for α < θ < β , then the area of the region R enclosed by the
polar plot of the curve r = f ( θ ) and the rays
θ = α and θ = β is:
Area ( R ) =
1
2
β
∫ [ f (θ ) ]
α
2
dθ
=
1
2
β
∫r
2
dθ
α
O
For each of the shaded regions displayed in figures 1 – 6 shown below, evaluate an appropriate
definite integral to determine its exact area.
1.
2.
r = 1 – cos θ
4.
3.
r = 2 cos θ
5.
r = θ
r = sin 2 θ
6.
r = 1 – sin θ
r = 2 cos 2θ