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Types of a Function
Chapter 2
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Types of
Functions
Polynomials
Radical
Functions
Rational
Functions
Absolute Value
Functions
Exponential
Functions
Logarithmic
Functions
Trigonometric
Functions
Hyperbolic
Functions
2
Polynomials
Linear Quadratic Cubic
3
• A polynomial of degree 1 is of the form 𝑓 𝑥 = 𝑚𝑥 + 𝑏 and so it is a linear
function.
• A polynomial of degree 2 is of the form 𝒇 𝒙 = 𝒂𝒙𝟐 + 𝒃𝒙 + 𝒄 and is called a
quadratic function.
• The parabola opens upward if 𝑎 > 0 and downward if 𝑎 < 0 .
• A polynomial of degree 3 is of the form 𝒇 𝒙 = 𝒂𝒙𝟑 + 𝒃𝒙𝟐 + 𝒄𝒙 + 𝒅 and is
called a cubic function.
4
slope Y-intercept
Completing Square
𝑥 ±
𝑎
2
2
−
𝑎
2
2
± 𝑏
5
Example 2.1
6
Sketch 𝑓 𝑥 = 𝑥2
+ 6𝑥 + 10
Completing the square, we write the equation of the graph as
y = 𝑥2
+ 6𝑥 + 10 = 𝑥 + 3 2
+ 1
This means we
obtain the
desired graph by
starting with the
parabola and
shifting 3 units to
the left and then
1 unit upward.
Base Graph
Rational Functions
Square Root Cubic Root
7
Sketch the Following Functions in Steps
8
𝑓 𝑥 = 𝑥 − 1 − 2
𝑓 𝑥 = 2 − 1 − 𝑥
𝑓 𝑥 = − −𝑥
Example 2.2
Example 2.2.a
9
Sketch 𝑓 𝑥 = 𝑥 − 1 − 2
Example 2.2.b
10
Sketch 𝑓 𝑥 = 2 − 1 − 𝑥
Example 2.2.c
11
Sketch 𝑓 𝑥 = − −𝑥
Some Special Radical Functions
12
Sketch the Following Functions in Steps
Example 2.3
𝑓 𝑥 =
1
𝑥 − 1
+ 3
𝑓 𝑥 =
1
(𝑥 − 1)2
+ 4
𝑓 𝑥 =
1
2(1 − 𝑥)3
+ 5
Example 2.3.a
14
Graph 𝑓 𝑥 =
1
𝑥−1
+ 3
Example 2.3.b
15
Graph 𝑓 𝑥 =
1
(𝑥−1)2 + 4
Example 2.3.c
16
Graph 𝑓 𝑥 =
1
2(1−𝑥)3 + 5
Challenging
Problem
Absolute Value Functions
17
𝑎 = 𝑎 𝑖𝑓 𝑎 ≥ 0
𝑎 = −𝑎 𝑖𝑓 𝑎 < 0
(Remember that if a is
negative, then "a is
positive.)
𝑥 = ቊ
−𝑥, 𝑥 < 0
𝑥, 𝑥 ≥ 0
Example 2.4
18
Sketch the Following Functions in Steps
𝑓 𝑥 = 𝑥 − 2 + 1
𝑓 𝑥 = 𝑥2
− 1
Example 2.4.a
19
Graph 𝑓 𝑥 = 𝑥2
− 1 in steps
We first graph the parabola
𝑓 𝑥 = 𝑥2
− 1 by shifting the parabola
𝑦 = 𝑥2 downward 1 unit. We see that
the graph lies below the x-axis when
− 1 < 𝑥 < 1, so we reflect that part of
the graph about the x-axis to obtain the
graph of 𝑓 𝑥 = 𝑥2
− 1
Example 2.4.b
20
Graph 𝑓 𝑥 = 𝑥 − 2 + 1 in steps
Try to sketch in steps and then find domain &
Range
𝑦 = (𝑥 + 1)2
𝑦 = 𝑥2
𝑦 = 𝑥2
+ 3
𝑦 = (𝑥 + 1)2
+3
𝑦 = 𝑥2
+ 2𝑥 + 1
𝑦 = 𝑥2
− 4𝑥 + 7
𝑦 = 2𝑥2
− 8𝑥 + 14
𝑦 =
2
𝑥 − 3
𝑦 =
2𝑥 − 3
𝑥 − 1
𝑦 = 𝑥 − 1 − 1
𝑦 =
3
𝑥 − 1 − 1
𝑦 = 1 − 𝑥2
𝑦 = 12 − 4𝑥 − 𝑥2 − 2
𝑦 =
2𝑥 − 3
𝑥 − 1
𝑦 = 𝑥 − 1 − 1
Trigonometric Functions
Sine Cosine Tangent
22
• An important property of the sine and cosine functions is that they are
periodic functions and have period 2𝜋.
• The period of tangent is 𝜋.
• The remaining three trigonometric functions (cosecant, secant, and cotangent)
are the reciprocals of the sine, cosine, and tangent functions; therefore, they
have the same period.
23
Notice that for both the sine and cosine functions the domain is and the range
is the closed interval . Thus, for all values of , we have
−1 ≤ 𝑠𝑖𝑛𝑥 ≤ 1 − 1 ≤ 𝑐𝑜𝑠𝑥 ≤ 1
or, in terms of absolute values, 𝑠𝑖𝑛𝑥 ≤ 1 𝑐𝑜𝑠𝑥 ≤ 1
Example 2.5 Sketch the Following Functions
𝑓(𝑥) = 1 + 4𝑐𝑜𝑠3𝑥
𝑓 𝑥 = 𝑠𝑖𝑛2𝑥
𝑓 𝑥 = 1 − 𝑠𝑖𝑛𝑥
𝑓(𝑥) =
1
4
𝑡𝑎𝑛 𝑥 −
𝜋
4
Example 2.5.a
25
Sketch the Graph 𝑓 𝑥 = 𝑠𝑖𝑛2𝑥
We obtain the graph of 𝑓 𝑥 from
that of 𝑓 𝑥 = 𝑠𝑖𝑛𝑥 by
compressing horizontally by a
factor of 2. Thus, whereas the
period of 𝑓 𝑥 = 𝑠𝑖𝑛𝑥 is 2𝜋, the
period of 𝑓 𝑥 = 𝑠𝑖𝑛2𝑥 is
2𝜋
2
= π .
Example 2.5.b
26
Sketch the Graph 𝑓 𝑥 = 1 − 𝑠𝑖𝑛𝑥
To obtain the graph of 𝑓 𝑥 = 1 −
𝑠𝑖𝑛𝑥, we again start with 𝑓 𝑥 =
𝑠𝑖𝑛𝑥 . We reflect about the x-axis
to get the graph of 𝑓 𝑥 = −𝑠𝑖𝑛𝑥
and then we shift 1 unit upward to
get 𝑓 𝑥 = 1 − 𝑠𝑖𝑛𝑥.
Example 2.5.c
27
Sketch The graph 𝑓(𝑥) =
1
4
𝑡𝑎𝑛 𝑥 −
𝜋
4
Example 2.5.d Sketch The Graph 𝑓(𝑥) = 1 + 4𝑐𝑜𝑠3𝑥
Trigonometric Functions
Cosecant Secant Cotangent
29
Basic Trigonometric Identities
30
𝑠𝑖𝑛2
𝜃 + 𝑐𝑜𝑠2
𝜃 = 1
𝑡𝑎𝑛2
𝜃 + 1 = 𝑠𝑒𝑐2
𝜃
1 + 𝑐𝑜𝑡2
𝜃 = 𝑐𝑠𝑐2
𝜃
sin −𝜃 = −𝑠𝑖𝑛𝜃
cos −𝜃 = 𝑐𝑜𝑠𝜃
cos 𝐴 + 𝐵 = 𝑐𝑜𝑠𝐴𝑐𝑜𝑠𝐵 − 𝑠𝑖𝑛𝐴𝑠𝑖𝑛𝐵
sin 𝐴 + 𝐵 = 𝑠𝑖𝑛𝐴𝑐𝑜𝑠𝐵 + 𝑐𝑜𝑠𝐴𝑠𝑖𝑛𝐵
𝑐𝑜𝑠2𝜃 = 𝑐𝑜𝑠2
𝜃 − 𝑠𝑖𝑛2
𝜃 = 2𝑐𝑜𝑠2
𝜃 − 1
𝑠𝑖𝑛2𝜃 = 2𝑠𝑖𝑛𝜃𝑐𝑜𝑠𝜃
𝑐𝑜𝑠2
𝜃 =
1 + 𝑐𝑜𝑠2𝜃
2
𝑠𝑖𝑛2
𝜃 =
1 − 𝑐𝑜𝑠2𝜃
2
31
tan2
𝜃 + 1 = sec2
𝑥
We start with the identity 𝑠𝑖𝑛2
𝜃 + 𝑐𝑜𝑠2
𝜃 = 1
Dividing both sides of this equation by 𝑐𝑜𝑠2
𝜃,
we obtain
𝑠𝑖𝑛2𝜃
𝑐𝑜𝑠2𝜃
+ 1 =
1
𝑐𝑜𝑠2𝜃
Since
𝑠𝑖𝑛𝜃
𝑐𝑜𝑠𝜃
= 𝑡𝑎𝑛𝜃 and
1
𝑐𝑜𝑠𝜃
= 𝑠𝑒𝑐𝜃, we
conclude that tan2
𝜃 + 1 = sec2
𝑥
Exponential Functions
32
𝑒𝑥+𝑦
= 𝑒𝑥
𝑒𝑦
𝑒𝑥−𝑦
=
𝑒𝑥
𝑒𝑦
(𝑒𝑥
)𝑦
= 𝑒𝑥𝑦
(𝑎𝑏)𝑥
= 𝑎𝑥
𝑏𝑦
𝑒−𝑥
=
1
𝑒𝑥
Example 2.6
33
𝑓 𝑥 = 𝑒𝑥+1
33
𝑓 𝑥 = 3 − 2𝑥
Sketch the Following Graph in Steps
𝑓 𝑥 =
1
2
𝑒−𝑥
− 1
𝑓 𝑥 = −(3𝑥
+ 2)
𝑓 𝑥 = 2𝑥
+ 1
𝑓 𝑥 = −3−𝑥
Example 2.6.a
34
Sketch the Graph 𝑓 𝑥 = 3 − 2𝑥
First, we reflect the graph
of 𝑦 = 2𝑥
about the x-axis
to get the graph of 𝑦 =
− 2𝑥
Base
graph
Then, we shift the
graph of 𝑦 = −2𝑥
upward 3 units to
obtain the graph of
𝑦 = 3 − 2𝑥
The Domain is ℝ
The Range is (-∞,3)
Example 2.6.b
35
Sketch the Graph 𝑓 𝑥 =
1
2
𝑒−𝑥
− 1
Base
graph
First, we reflect the graph
of 𝑦 = 𝑒𝑥 about the y-axis
to get the graph of 𝑦 =
𝑒−𝑥
. (Notice that the graph
crosses the y-axis with a
slope of -1)
Then, Then we
compress the graph
vertically by a factor
of 2 to obtain the
graph of 𝑦 =
1
2
𝑒−𝑥
Finally, we shift the
graph downward one
unit to get 𝑓 𝑥 =
1
2
𝑒−𝑥 − 1
The Domain is ℝ
The Range is (-1, ∞)
Example 2.6.c
36
Sketch the Graph 𝑓 x = e𝑥+1
36
Example 2.6.d
37
Sketch the Graph 𝑓 x = −(3𝑥
+ 2)
37
Example 2.6.e
38
Sketch the Graph 𝑓 x = 2𝑥
+ 1
38
Example 2.6.f
39
Sketch the Graph 𝑓 x = −3−𝑥
39
Logarithmic Functions
40
log𝑎(𝑎𝑥) = 𝑥 𝑥 = ℝ
ln 𝑒𝑥 = 𝑥
𝑙𝑛𝑥 = 𝑦 ⇔ 𝑒𝑦
= 𝑥
log𝑎(𝑥𝑟) = rlog𝑎 𝑥
log𝑎(𝑥𝑦) = log𝑎 𝑥 + log𝑎 𝑦 log𝑎
𝑥
𝑦
= log𝑎 𝑥 − log𝑎 𝑦
𝑎log𝑎 𝑥 = 𝑥 𝑥 > 0
log𝑎(𝑥) =
𝑙𝑛𝑥
𝑙𝑛𝑎
for any positive numbers
𝑙𝑛𝑒 = 1
𝑒𝑙𝑛𝑥 = 𝑥 𝑥 > 0
Example 2.7
41
Simplify the Following Expressions
41
𝑒ln(7.2)
𝑙𝑛
sin2 𝑥 tan4 𝑥
𝑥2 + 1 2
𝑙𝑛
4 𝑥2 + 1
𝑥2 − 1
𝑙𝑛𝑒(2 ln 𝑥)
ln[ln 𝑒𝑒 ]
2ln( 𝑒)
𝑒x−ln(𝑥)
𝑒ln(𝑥2+𝑦2)
𝑒 ln 𝑥 −ln 𝑦
𝑒−ln(𝑥2)
ln 𝑒𝑒𝑥
𝑙𝑛
𝑥3 + 1 4sin2 𝑥
3
𝑥
ln(𝑠𝑖𝑛𝜃) − ln
𝑠𝑖𝑛𝜃
5
ln(3𝑥2 − 9𝑥) + ln
1
3𝑥
ln(𝑠𝑒𝑐𝜃) + ln(𝑐𝑜𝑠𝜃)
3𝑙𝑛
3
𝑡2 − 1 − ln(𝑡 + 1)
𝑒5−3𝑥
= 10
Example 2.8
42
Solve the Equation 𝑒5−3𝑥
= 10
42
𝑙𝑛𝑒5−3𝑥
= 𝑙𝑛10
5 − 3𝑥 = 𝑙𝑛10
3𝑥 = 5 − 𝑙𝑛10
𝑥 =
1
3
5 − 𝑙𝑛10
We take natural logarithms
of both sides of the equation
Apply ln 𝑒𝑥 = 𝑥
𝑒−ln(𝑥2)
𝑒
ln
1
𝑥2 =
1
𝑥2
43
Example 2.8
𝑒ln(7.2)
7.2
44
Example 2.8
𝑒 ln 𝑥 −ln 𝑦
𝑒 ln 𝑥 −ln 𝑦
= ൝
𝑒𝑙𝑛𝑥−𝑙𝑛𝑦
𝑥 ≥ 𝑦
𝑒𝑙𝑛𝑦−𝑙𝑛𝑥 𝑥 < 𝑦
= ቐ
ൗ
𝑥
𝑦 𝑥 ≥ 𝑦
ൗ
𝑦
𝑥 𝑥 < 𝑦
45
Example 2.8
𝑒ln(𝑥2+𝑦2)
𝑥2 + 𝑦2
46
Example 2.8
𝑒x−ln(𝑥)
𝑒𝑥
𝑒𝑙𝑛𝑥
=
𝑒𝑥
𝑥
47
Example 2.8
2ln( 𝑒)
2 ln 𝑒
1
2 = 𝑙𝑛𝑒 = 1
48
Example 2.8
ln 𝑒𝑒𝑥
𝑒𝑥
49
Example 2.8
𝑙𝑛𝑒(2 ln 𝑥)
ln 𝑒𝑙𝑛𝑥2
= 𝑙𝑛𝑥2
= 2𝑙𝑛𝑥
50
Example 2.8
𝑙𝑛
4 𝑥2 + 1
𝑥2 − 1
𝑙𝑛
4 𝑥2 + 1
𝑥2 − 1
=
1
4
𝑙𝑛
𝑥2
+ 1
𝑥2 − 1
=
1
4
[ln 𝑥2
+ 1 − ln(𝑥2
− 1)
51
Example 2.8
𝑙𝑛
sin2
𝑥 tan4
𝑥
𝑥2 + 1 2
ln sin2
𝑥 + ln tan4
𝑥 − ln 𝑥2
+ 1 2
= 2 ln 𝑠𝑖𝑛𝑥 + 4 ln 𝑡𝑎𝑛𝑥 − 2ln(𝑥2
+ 1)
52
Example 2.8
𝑙𝑛
𝑥3
+ 1 4
sin2
𝑥
3
𝑥
𝑙𝑛
𝑥3
+ 1 4
sin2
𝑥
3
𝑥
= 4 ln 𝑥3
+ 1 + 2 ln 𝑠𝑖𝑛𝑥 −
𝑙𝑛𝑥
3
53
Example 2.8
ln(𝑠𝑖𝑛𝜃) − ln
𝑠𝑖𝑛𝜃
5
ln(𝑠𝑖𝑛𝜃) − ln
𝑠𝑖𝑛𝜃
5
= ln 𝑠𝑖𝑛𝜃 − ln 𝑠𝑖𝑛𝜃 − −𝑙𝑛5 = 𝑙𝑛5
54
Example 2.8
ln(3𝑥2
− 9𝑥) + ln
1
3𝑥
= 𝑙𝑛3𝑥 𝑥 − 3 + 𝑙𝑛
1
3𝑥
= 𝑙𝑛 3𝑥 + 𝑙𝑛 𝑥 − 3 − 𝑙𝑛 3𝑥
= 𝑙𝑛(𝑥 − 3)
55
Example 2.8
ln(𝑠𝑒𝑐𝜃) + ln(𝑐𝑜𝑠𝜃)
ln 𝑐𝑜𝑠𝜃 −1
+ ln 𝑐𝑜𝑠𝜃 = 0
56
Example 2.8
3𝑙𝑛
3
𝑡2 − 1 − ln(𝑡 + 1)
ln 𝑡2
− 1 − ln 𝑡 + 1 = ln 𝑡 − 1 𝑡 + 1 − ln 𝑡 + 1 = ln(𝑡 − 1)
57
Example 2.8
ln[ln 𝑒𝑒
]
𝑙𝑛𝑒 = 1
58
Example 2.8
Example 2.9
59
Sketch the Following Functions
59
𝑦 = ln 𝑥 − 2 − 1 𝑓 𝑥 = ln(𝑥 + 2)
𝑓 𝑥 = 𝑙𝑛𝑥 + 2
𝑓 𝑥 = 1 + ln(−𝑥)
𝑓 𝑥 = 𝑙𝑛 𝑥
𝑓 𝑥 = 2 − log(2 − 𝑥)
Example 2.9
60
Sketch the Graph 𝑦 = ln 𝑥 − 2 − 1
60
We start with the
graph of 𝑦 = 𝑙𝑛𝑥
Using the transformations, we
shift it 2 units to the right to get
the graph of 𝑦 = ln(𝑥 − 2)
Then we shift it 1 unit
downward to get the
graph of 𝑦 = 𝑥 − 2 − 1
Example 2.9
61
Sketch the Graph 𝑓 𝑥 = ln(𝑥 + 2)
61
62
Sketch the Graph 𝑓 𝑥 = 𝑙𝑛𝑥 + 2
62
Example 2.9
63
Sketch the Graph 𝑓 𝑥 = 1 + ln(−𝑥)
63
Example 2.9
64
Sketch the Graph 𝑓 𝑥 = 𝑙𝑛 𝑥
64
Example 2.9
65
Sketch the Graph 𝑓 𝑥 = 2 − log(2 − 𝑥)
65
Example 2.9
Hyperbolic Functions
Hyperbolic Sine of
x
𝑠𝑖𝑛ℎ𝑥 =
𝑒𝑥
− 𝑒−𝑥
2
𝑠𝑖𝑛ℎ0 = 0
Hyperbolic Cosine
of x
𝑐𝑜𝑠ℎ𝑥 =
𝑒𝑥
+ 𝑒−𝑥
2
𝑐𝑜𝑠ℎ0 = 1
Hyperbolic of
Tangent of x
𝑡𝑎𝑛ℎ𝑥 =
𝑠𝑖𝑛ℎ𝑥
𝑐𝑜𝑠ℎ𝑥
=
𝑒𝑥 − 𝑒−𝑥
𝑒𝑥 + 𝑒−𝑥
−1 < 𝑡𝑎𝑛ℎ𝑥 < 1
66
Exercise 2.10
cosh 2𝑙𝑛𝑥
Simplify the Following Expressions
sinh 5𝑙𝑛𝑥 cosh(𝑙𝑛3)
sinh(𝑙𝑛2)
If 𝑠𝑖𝑛ℎ𝑥 =
3
4
, find the values of the remaining five hyperbolic functions.
sinh(𝑙𝑛2)
Using the definition of sinh function, we write
sinh 𝑙𝑛2 =
𝑒𝑙𝑛2 − 𝑒−𝑙𝑛2
2
=
2 −
1
2
2
=
3
4
68
sinh 5𝑙𝑛𝑥
Using the definition of sinh function, we write
sinh 5𝑙𝑛𝑥 =
𝑒5𝑙𝑛𝑥 − 𝑒−5𝑙𝑛𝑥
2
=
𝑒ln 𝑥5
− 𝑒𝑙𝑛𝑥−5
2
=
𝑥5 − 𝑥−5
2
69
cosh(𝑙𝑛3)
Using the definition of cosh function, we write
cosh 𝑙𝑛3 =
𝑒ln 3 + 𝑒−𝑙𝑛3
2
=
3 +
1
3
2
=
10
6
=
5
3
70
If 𝑠𝑖𝑛ℎ𝑥 =
3
4
, find the values of the remaining five
hyperbolic functions.
Using the identity cosh2 𝑥 − sinh2 𝑥 = 1, we see that
cosh2
𝑥 = 1 +
3
4
2
=
25
16
Since 𝑐𝑜𝑠ℎ𝑥 ≥ 1 for all x, we must have cosh 𝑥 =
5
4
.
Then, using the definitions for the other hyperbolic functions, we conclude
that 𝑡𝑎𝑛ℎ𝑥 =
3
5
, 𝑐𝑠𝑐ℎ𝑥 =
4
3
, 𝑠𝑒𝑐ℎ𝑥 =
4
5
, 𝑐𝑜𝑡ℎ𝑥 =
5
3
.
71
Hyperbolic Functions
Hyperbolic
cotangent of x
𝑐𝑜𝑡ℎ𝑥 =
𝑐𝑜𝑠ℎ𝑥
𝑠𝑖𝑛ℎ𝑥
=
𝑒𝑥
+ 𝑒−𝑥
𝑒𝑥 − 𝑒−𝑥
Hyperbolic
secant of x
𝑠𝑒𝑐ℎ𝑥 =
1
𝑐𝑜𝑠ℎ𝑥
=
2
𝑒𝑥 + 𝑒−𝑥
0 < 𝑠𝑒𝑐ℎ𝑥 ≤ 1
Hyperbolic of
cosecant of x
cscℎ𝑥 =
1
𝑠𝑖𝑛ℎ𝑥
=
2
𝑒𝑥−𝑒−𝑥
72
Exercise 2.11
cosh −𝑥 = 𝑐𝑜𝑠ℎ𝑥
Prove the Following Hyperbolic Functions
sinh −𝑥 = −𝑠𝑖𝑛ℎ𝑥
𝑐𝑜𝑠ℎ𝑥 + 𝑠𝑖𝑛ℎ𝑥 = 𝑒𝑥
𝑐𝑜𝑠ℎ𝑥 − 𝑠𝑖𝑛ℎ𝑥 = 𝑒−𝑥
coth2
𝑥 − 1 = csch2
𝑥
sinh 𝑥 ± 𝑦 = 𝑠𝑖𝑛ℎ𝑥𝑐𝑜𝑠ℎ𝑦 ± 𝑐𝑜𝑠ℎ𝑥𝑠𝑖𝑛ℎ𝑦
cosh 𝑥 ± 𝑦 = 𝑐𝑜𝑠ℎ𝑥𝑐𝑜𝑠ℎ𝑦 ± 𝑠𝑖𝑛ℎ𝑥𝑠𝑖𝑛ℎ𝑦
tanh 𝑙𝑛𝑥 =
𝑥2 − 1
𝑥2 + 1
1 + 𝑡𝑎𝑛ℎ𝑥
1 − 𝑡𝑎𝑛ℎ𝑥
= 𝑒2𝑥
Assignment
2.1
2.1.1. 𝑦 = 𝑥2
+ 6𝑥 − 8
2.1.2. 𝑦 = 7 + 2𝑥 − 𝑥2
2.1.3. 𝑦 = 2𝑥 + 5
2.1.4. 𝑦 = 2𝑥 + 5
2.1.5. 𝑦 = 2 − 𝑥 + 3
2.1.6. 𝑦 =
3
x+2
2.1.7. 𝑦 =
𝑥−4
2𝑥+3
2.1.8. 𝑦 = −2 − 4𝑥 − 𝑥2
2.1.9. 𝑦 = −𝑠𝑖𝑛2𝑥
2.1.10. 𝑦 =
1
2
1 + 𝑒𝑥
2.1.11. 𝑓 𝑥 =
1
𝑥+2
2.1.12. 𝑓 𝑥 = 5𝑥+1
+ 2
2.1.13. 𝑓 𝑥 = 3 + 𝑙𝑛𝑥
2.1.14. 𝑓 𝑥 = ln 𝑥 − 1
2.1.15. 𝑓 𝑥 = 𝑙𝑜𝑔𝑥 − 1
2.1.16. 𝑓 𝑥 = ln −𝑥
2.1.17. 𝑓 𝑥 = 𝑒𝑥
+ 2
2.1.18. 𝑓 𝑥 = 𝑒−𝑥
− 1
2.1.19. 𝑓 𝑥 = 4 cos 2𝑥 −
𝜋
2
2.1.20. 𝑓 𝑥 = −3sin(𝜋𝑥 + 2)
74
Graph each of the following functions
then from the graph find its the domain
and range.

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Chapter 2 - Types of a Function.pdf

  • 1. Types of a Function Chapter 2 This Photo by Unknown Author is licensed under CC BY
  • 4. • A polynomial of degree 1 is of the form 𝑓 𝑥 = 𝑚𝑥 + 𝑏 and so it is a linear function. • A polynomial of degree 2 is of the form 𝒇 𝒙 = 𝒂𝒙𝟐 + 𝒃𝒙 + 𝒄 and is called a quadratic function. • The parabola opens upward if 𝑎 > 0 and downward if 𝑎 < 0 . • A polynomial of degree 3 is of the form 𝒇 𝒙 = 𝒂𝒙𝟑 + 𝒃𝒙𝟐 + 𝒄𝒙 + 𝒅 and is called a cubic function. 4 slope Y-intercept
  • 6. Example 2.1 6 Sketch 𝑓 𝑥 = 𝑥2 + 6𝑥 + 10 Completing the square, we write the equation of the graph as y = 𝑥2 + 6𝑥 + 10 = 𝑥 + 3 2 + 1 This means we obtain the desired graph by starting with the parabola and shifting 3 units to the left and then 1 unit upward. Base Graph
  • 8. Sketch the Following Functions in Steps 8 𝑓 𝑥 = 𝑥 − 1 − 2 𝑓 𝑥 = 2 − 1 − 𝑥 𝑓 𝑥 = − −𝑥 Example 2.2
  • 9. Example 2.2.a 9 Sketch 𝑓 𝑥 = 𝑥 − 1 − 2
  • 10. Example 2.2.b 10 Sketch 𝑓 𝑥 = 2 − 1 − 𝑥
  • 11. Example 2.2.c 11 Sketch 𝑓 𝑥 = − −𝑥
  • 12. Some Special Radical Functions 12
  • 13. Sketch the Following Functions in Steps Example 2.3 𝑓 𝑥 = 1 𝑥 − 1 + 3 𝑓 𝑥 = 1 (𝑥 − 1)2 + 4 𝑓 𝑥 = 1 2(1 − 𝑥)3 + 5
  • 14. Example 2.3.a 14 Graph 𝑓 𝑥 = 1 𝑥−1 + 3
  • 15. Example 2.3.b 15 Graph 𝑓 𝑥 = 1 (𝑥−1)2 + 4
  • 16. Example 2.3.c 16 Graph 𝑓 𝑥 = 1 2(1−𝑥)3 + 5 Challenging Problem
  • 17. Absolute Value Functions 17 𝑎 = 𝑎 𝑖𝑓 𝑎 ≥ 0 𝑎 = −𝑎 𝑖𝑓 𝑎 < 0 (Remember that if a is negative, then "a is positive.) 𝑥 = ቊ −𝑥, 𝑥 < 0 𝑥, 𝑥 ≥ 0
  • 18. Example 2.4 18 Sketch the Following Functions in Steps 𝑓 𝑥 = 𝑥 − 2 + 1 𝑓 𝑥 = 𝑥2 − 1
  • 19. Example 2.4.a 19 Graph 𝑓 𝑥 = 𝑥2 − 1 in steps We first graph the parabola 𝑓 𝑥 = 𝑥2 − 1 by shifting the parabola 𝑦 = 𝑥2 downward 1 unit. We see that the graph lies below the x-axis when − 1 < 𝑥 < 1, so we reflect that part of the graph about the x-axis to obtain the graph of 𝑓 𝑥 = 𝑥2 − 1
  • 20. Example 2.4.b 20 Graph 𝑓 𝑥 = 𝑥 − 2 + 1 in steps
  • 21. Try to sketch in steps and then find domain & Range 𝑦 = (𝑥 + 1)2 𝑦 = 𝑥2 𝑦 = 𝑥2 + 3 𝑦 = (𝑥 + 1)2 +3 𝑦 = 𝑥2 + 2𝑥 + 1 𝑦 = 𝑥2 − 4𝑥 + 7 𝑦 = 2𝑥2 − 8𝑥 + 14 𝑦 = 2 𝑥 − 3 𝑦 = 2𝑥 − 3 𝑥 − 1 𝑦 = 𝑥 − 1 − 1 𝑦 = 3 𝑥 − 1 − 1 𝑦 = 1 − 𝑥2 𝑦 = 12 − 4𝑥 − 𝑥2 − 2 𝑦 = 2𝑥 − 3 𝑥 − 1 𝑦 = 𝑥 − 1 − 1
  • 23. • An important property of the sine and cosine functions is that they are periodic functions and have period 2𝜋. • The period of tangent is 𝜋. • The remaining three trigonometric functions (cosecant, secant, and cotangent) are the reciprocals of the sine, cosine, and tangent functions; therefore, they have the same period. 23 Notice that for both the sine and cosine functions the domain is and the range is the closed interval . Thus, for all values of , we have −1 ≤ 𝑠𝑖𝑛𝑥 ≤ 1 − 1 ≤ 𝑐𝑜𝑠𝑥 ≤ 1 or, in terms of absolute values, 𝑠𝑖𝑛𝑥 ≤ 1 𝑐𝑜𝑠𝑥 ≤ 1
  • 24. Example 2.5 Sketch the Following Functions 𝑓(𝑥) = 1 + 4𝑐𝑜𝑠3𝑥 𝑓 𝑥 = 𝑠𝑖𝑛2𝑥 𝑓 𝑥 = 1 − 𝑠𝑖𝑛𝑥 𝑓(𝑥) = 1 4 𝑡𝑎𝑛 𝑥 − 𝜋 4
  • 25. Example 2.5.a 25 Sketch the Graph 𝑓 𝑥 = 𝑠𝑖𝑛2𝑥 We obtain the graph of 𝑓 𝑥 from that of 𝑓 𝑥 = 𝑠𝑖𝑛𝑥 by compressing horizontally by a factor of 2. Thus, whereas the period of 𝑓 𝑥 = 𝑠𝑖𝑛𝑥 is 2𝜋, the period of 𝑓 𝑥 = 𝑠𝑖𝑛2𝑥 is 2𝜋 2 = π .
  • 26. Example 2.5.b 26 Sketch the Graph 𝑓 𝑥 = 1 − 𝑠𝑖𝑛𝑥 To obtain the graph of 𝑓 𝑥 = 1 − 𝑠𝑖𝑛𝑥, we again start with 𝑓 𝑥 = 𝑠𝑖𝑛𝑥 . We reflect about the x-axis to get the graph of 𝑓 𝑥 = −𝑠𝑖𝑛𝑥 and then we shift 1 unit upward to get 𝑓 𝑥 = 1 − 𝑠𝑖𝑛𝑥.
  • 27. Example 2.5.c 27 Sketch The graph 𝑓(𝑥) = 1 4 𝑡𝑎𝑛 𝑥 − 𝜋 4
  • 28. Example 2.5.d Sketch The Graph 𝑓(𝑥) = 1 + 4𝑐𝑜𝑠3𝑥
  • 30. Basic Trigonometric Identities 30 𝑠𝑖𝑛2 𝜃 + 𝑐𝑜𝑠2 𝜃 = 1 𝑡𝑎𝑛2 𝜃 + 1 = 𝑠𝑒𝑐2 𝜃 1 + 𝑐𝑜𝑡2 𝜃 = 𝑐𝑠𝑐2 𝜃 sin −𝜃 = −𝑠𝑖𝑛𝜃 cos −𝜃 = 𝑐𝑜𝑠𝜃 cos 𝐴 + 𝐵 = 𝑐𝑜𝑠𝐴𝑐𝑜𝑠𝐵 − 𝑠𝑖𝑛𝐴𝑠𝑖𝑛𝐵 sin 𝐴 + 𝐵 = 𝑠𝑖𝑛𝐴𝑐𝑜𝑠𝐵 + 𝑐𝑜𝑠𝐴𝑠𝑖𝑛𝐵 𝑐𝑜𝑠2𝜃 = 𝑐𝑜𝑠2 𝜃 − 𝑠𝑖𝑛2 𝜃 = 2𝑐𝑜𝑠2 𝜃 − 1 𝑠𝑖𝑛2𝜃 = 2𝑠𝑖𝑛𝜃𝑐𝑜𝑠𝜃 𝑐𝑜𝑠2 𝜃 = 1 + 𝑐𝑜𝑠2𝜃 2 𝑠𝑖𝑛2 𝜃 = 1 − 𝑐𝑜𝑠2𝜃 2
  • 31. 31 tan2 𝜃 + 1 = sec2 𝑥 We start with the identity 𝑠𝑖𝑛2 𝜃 + 𝑐𝑜𝑠2 𝜃 = 1 Dividing both sides of this equation by 𝑐𝑜𝑠2 𝜃, we obtain 𝑠𝑖𝑛2𝜃 𝑐𝑜𝑠2𝜃 + 1 = 1 𝑐𝑜𝑠2𝜃 Since 𝑠𝑖𝑛𝜃 𝑐𝑜𝑠𝜃 = 𝑡𝑎𝑛𝜃 and 1 𝑐𝑜𝑠𝜃 = 𝑠𝑒𝑐𝜃, we conclude that tan2 𝜃 + 1 = sec2 𝑥
  • 32. Exponential Functions 32 𝑒𝑥+𝑦 = 𝑒𝑥 𝑒𝑦 𝑒𝑥−𝑦 = 𝑒𝑥 𝑒𝑦 (𝑒𝑥 )𝑦 = 𝑒𝑥𝑦 (𝑎𝑏)𝑥 = 𝑎𝑥 𝑏𝑦 𝑒−𝑥 = 1 𝑒𝑥
  • 33. Example 2.6 33 𝑓 𝑥 = 𝑒𝑥+1 33 𝑓 𝑥 = 3 − 2𝑥 Sketch the Following Graph in Steps 𝑓 𝑥 = 1 2 𝑒−𝑥 − 1 𝑓 𝑥 = −(3𝑥 + 2) 𝑓 𝑥 = 2𝑥 + 1 𝑓 𝑥 = −3−𝑥
  • 34. Example 2.6.a 34 Sketch the Graph 𝑓 𝑥 = 3 − 2𝑥 First, we reflect the graph of 𝑦 = 2𝑥 about the x-axis to get the graph of 𝑦 = − 2𝑥 Base graph Then, we shift the graph of 𝑦 = −2𝑥 upward 3 units to obtain the graph of 𝑦 = 3 − 2𝑥 The Domain is ℝ The Range is (-∞,3)
  • 35. Example 2.6.b 35 Sketch the Graph 𝑓 𝑥 = 1 2 𝑒−𝑥 − 1 Base graph First, we reflect the graph of 𝑦 = 𝑒𝑥 about the y-axis to get the graph of 𝑦 = 𝑒−𝑥 . (Notice that the graph crosses the y-axis with a slope of -1) Then, Then we compress the graph vertically by a factor of 2 to obtain the graph of 𝑦 = 1 2 𝑒−𝑥 Finally, we shift the graph downward one unit to get 𝑓 𝑥 = 1 2 𝑒−𝑥 − 1 The Domain is ℝ The Range is (-1, ∞)
  • 36. Example 2.6.c 36 Sketch the Graph 𝑓 x = e𝑥+1 36
  • 37. Example 2.6.d 37 Sketch the Graph 𝑓 x = −(3𝑥 + 2) 37
  • 38. Example 2.6.e 38 Sketch the Graph 𝑓 x = 2𝑥 + 1 38
  • 39. Example 2.6.f 39 Sketch the Graph 𝑓 x = −3−𝑥 39
  • 40. Logarithmic Functions 40 log𝑎(𝑎𝑥) = 𝑥 𝑥 = ℝ ln 𝑒𝑥 = 𝑥 𝑙𝑛𝑥 = 𝑦 ⇔ 𝑒𝑦 = 𝑥 log𝑎(𝑥𝑟) = rlog𝑎 𝑥 log𝑎(𝑥𝑦) = log𝑎 𝑥 + log𝑎 𝑦 log𝑎 𝑥 𝑦 = log𝑎 𝑥 − log𝑎 𝑦 𝑎log𝑎 𝑥 = 𝑥 𝑥 > 0 log𝑎(𝑥) = 𝑙𝑛𝑥 𝑙𝑛𝑎 for any positive numbers 𝑙𝑛𝑒 = 1 𝑒𝑙𝑛𝑥 = 𝑥 𝑥 > 0
  • 41. Example 2.7 41 Simplify the Following Expressions 41 𝑒ln(7.2) 𝑙𝑛 sin2 𝑥 tan4 𝑥 𝑥2 + 1 2 𝑙𝑛 4 𝑥2 + 1 𝑥2 − 1 𝑙𝑛𝑒(2 ln 𝑥) ln[ln 𝑒𝑒 ] 2ln( 𝑒) 𝑒x−ln(𝑥) 𝑒ln(𝑥2+𝑦2) 𝑒 ln 𝑥 −ln 𝑦 𝑒−ln(𝑥2) ln 𝑒𝑒𝑥 𝑙𝑛 𝑥3 + 1 4sin2 𝑥 3 𝑥 ln(𝑠𝑖𝑛𝜃) − ln 𝑠𝑖𝑛𝜃 5 ln(3𝑥2 − 9𝑥) + ln 1 3𝑥 ln(𝑠𝑒𝑐𝜃) + ln(𝑐𝑜𝑠𝜃) 3𝑙𝑛 3 𝑡2 − 1 − ln(𝑡 + 1) 𝑒5−3𝑥 = 10
  • 42. Example 2.8 42 Solve the Equation 𝑒5−3𝑥 = 10 42 𝑙𝑛𝑒5−3𝑥 = 𝑙𝑛10 5 − 3𝑥 = 𝑙𝑛10 3𝑥 = 5 − 𝑙𝑛10 𝑥 = 1 3 5 − 𝑙𝑛10 We take natural logarithms of both sides of the equation Apply ln 𝑒𝑥 = 𝑥
  • 45. 𝑒 ln 𝑥 −ln 𝑦 𝑒 ln 𝑥 −ln 𝑦 = ൝ 𝑒𝑙𝑛𝑥−𝑙𝑛𝑦 𝑥 ≥ 𝑦 𝑒𝑙𝑛𝑦−𝑙𝑛𝑥 𝑥 < 𝑦 = ቐ ൗ 𝑥 𝑦 𝑥 ≥ 𝑦 ൗ 𝑦 𝑥 𝑥 < 𝑦 45 Example 2.8
  • 48. 2ln( 𝑒) 2 ln 𝑒 1 2 = 𝑙𝑛𝑒 = 1 48 Example 2.8
  • 50. 𝑙𝑛𝑒(2 ln 𝑥) ln 𝑒𝑙𝑛𝑥2 = 𝑙𝑛𝑥2 = 2𝑙𝑛𝑥 50 Example 2.8
  • 51. 𝑙𝑛 4 𝑥2 + 1 𝑥2 − 1 𝑙𝑛 4 𝑥2 + 1 𝑥2 − 1 = 1 4 𝑙𝑛 𝑥2 + 1 𝑥2 − 1 = 1 4 [ln 𝑥2 + 1 − ln(𝑥2 − 1) 51 Example 2.8
  • 52. 𝑙𝑛 sin2 𝑥 tan4 𝑥 𝑥2 + 1 2 ln sin2 𝑥 + ln tan4 𝑥 − ln 𝑥2 + 1 2 = 2 ln 𝑠𝑖𝑛𝑥 + 4 ln 𝑡𝑎𝑛𝑥 − 2ln(𝑥2 + 1) 52 Example 2.8
  • 53. 𝑙𝑛 𝑥3 + 1 4 sin2 𝑥 3 𝑥 𝑙𝑛 𝑥3 + 1 4 sin2 𝑥 3 𝑥 = 4 ln 𝑥3 + 1 + 2 ln 𝑠𝑖𝑛𝑥 − 𝑙𝑛𝑥 3 53 Example 2.8
  • 54. ln(𝑠𝑖𝑛𝜃) − ln 𝑠𝑖𝑛𝜃 5 ln(𝑠𝑖𝑛𝜃) − ln 𝑠𝑖𝑛𝜃 5 = ln 𝑠𝑖𝑛𝜃 − ln 𝑠𝑖𝑛𝜃 − −𝑙𝑛5 = 𝑙𝑛5 54 Example 2.8
  • 55. ln(3𝑥2 − 9𝑥) + ln 1 3𝑥 = 𝑙𝑛3𝑥 𝑥 − 3 + 𝑙𝑛 1 3𝑥 = 𝑙𝑛 3𝑥 + 𝑙𝑛 𝑥 − 3 − 𝑙𝑛 3𝑥 = 𝑙𝑛(𝑥 − 3) 55 Example 2.8
  • 56. ln(𝑠𝑒𝑐𝜃) + ln(𝑐𝑜𝑠𝜃) ln 𝑐𝑜𝑠𝜃 −1 + ln 𝑐𝑜𝑠𝜃 = 0 56 Example 2.8
  • 57. 3𝑙𝑛 3 𝑡2 − 1 − ln(𝑡 + 1) ln 𝑡2 − 1 − ln 𝑡 + 1 = ln 𝑡 − 1 𝑡 + 1 − ln 𝑡 + 1 = ln(𝑡 − 1) 57 Example 2.8
  • 59. Example 2.9 59 Sketch the Following Functions 59 𝑦 = ln 𝑥 − 2 − 1 𝑓 𝑥 = ln(𝑥 + 2) 𝑓 𝑥 = 𝑙𝑛𝑥 + 2 𝑓 𝑥 = 1 + ln(−𝑥) 𝑓 𝑥 = 𝑙𝑛 𝑥 𝑓 𝑥 = 2 − log(2 − 𝑥)
  • 60. Example 2.9 60 Sketch the Graph 𝑦 = ln 𝑥 − 2 − 1 60 We start with the graph of 𝑦 = 𝑙𝑛𝑥 Using the transformations, we shift it 2 units to the right to get the graph of 𝑦 = ln(𝑥 − 2) Then we shift it 1 unit downward to get the graph of 𝑦 = 𝑥 − 2 − 1
  • 61. Example 2.9 61 Sketch the Graph 𝑓 𝑥 = ln(𝑥 + 2) 61
  • 62. 62 Sketch the Graph 𝑓 𝑥 = 𝑙𝑛𝑥 + 2 62 Example 2.9
  • 63. 63 Sketch the Graph 𝑓 𝑥 = 1 + ln(−𝑥) 63 Example 2.9
  • 64. 64 Sketch the Graph 𝑓 𝑥 = 𝑙𝑛 𝑥 64 Example 2.9
  • 65. 65 Sketch the Graph 𝑓 𝑥 = 2 − log(2 − 𝑥) 65 Example 2.9
  • 66. Hyperbolic Functions Hyperbolic Sine of x 𝑠𝑖𝑛ℎ𝑥 = 𝑒𝑥 − 𝑒−𝑥 2 𝑠𝑖𝑛ℎ0 = 0 Hyperbolic Cosine of x 𝑐𝑜𝑠ℎ𝑥 = 𝑒𝑥 + 𝑒−𝑥 2 𝑐𝑜𝑠ℎ0 = 1 Hyperbolic of Tangent of x 𝑡𝑎𝑛ℎ𝑥 = 𝑠𝑖𝑛ℎ𝑥 𝑐𝑜𝑠ℎ𝑥 = 𝑒𝑥 − 𝑒−𝑥 𝑒𝑥 + 𝑒−𝑥 −1 < 𝑡𝑎𝑛ℎ𝑥 < 1 66
  • 67. Exercise 2.10 cosh 2𝑙𝑛𝑥 Simplify the Following Expressions sinh 5𝑙𝑛𝑥 cosh(𝑙𝑛3) sinh(𝑙𝑛2) If 𝑠𝑖𝑛ℎ𝑥 = 3 4 , find the values of the remaining five hyperbolic functions.
  • 68. sinh(𝑙𝑛2) Using the definition of sinh function, we write sinh 𝑙𝑛2 = 𝑒𝑙𝑛2 − 𝑒−𝑙𝑛2 2 = 2 − 1 2 2 = 3 4 68
  • 69. sinh 5𝑙𝑛𝑥 Using the definition of sinh function, we write sinh 5𝑙𝑛𝑥 = 𝑒5𝑙𝑛𝑥 − 𝑒−5𝑙𝑛𝑥 2 = 𝑒ln 𝑥5 − 𝑒𝑙𝑛𝑥−5 2 = 𝑥5 − 𝑥−5 2 69
  • 70. cosh(𝑙𝑛3) Using the definition of cosh function, we write cosh 𝑙𝑛3 = 𝑒ln 3 + 𝑒−𝑙𝑛3 2 = 3 + 1 3 2 = 10 6 = 5 3 70
  • 71. If 𝑠𝑖𝑛ℎ𝑥 = 3 4 , find the values of the remaining five hyperbolic functions. Using the identity cosh2 𝑥 − sinh2 𝑥 = 1, we see that cosh2 𝑥 = 1 + 3 4 2 = 25 16 Since 𝑐𝑜𝑠ℎ𝑥 ≥ 1 for all x, we must have cosh 𝑥 = 5 4 . Then, using the definitions for the other hyperbolic functions, we conclude that 𝑡𝑎𝑛ℎ𝑥 = 3 5 , 𝑐𝑠𝑐ℎ𝑥 = 4 3 , 𝑠𝑒𝑐ℎ𝑥 = 4 5 , 𝑐𝑜𝑡ℎ𝑥 = 5 3 . 71
  • 72. Hyperbolic Functions Hyperbolic cotangent of x 𝑐𝑜𝑡ℎ𝑥 = 𝑐𝑜𝑠ℎ𝑥 𝑠𝑖𝑛ℎ𝑥 = 𝑒𝑥 + 𝑒−𝑥 𝑒𝑥 − 𝑒−𝑥 Hyperbolic secant of x 𝑠𝑒𝑐ℎ𝑥 = 1 𝑐𝑜𝑠ℎ𝑥 = 2 𝑒𝑥 + 𝑒−𝑥 0 < 𝑠𝑒𝑐ℎ𝑥 ≤ 1 Hyperbolic of cosecant of x cscℎ𝑥 = 1 𝑠𝑖𝑛ℎ𝑥 = 2 𝑒𝑥−𝑒−𝑥 72
  • 73. Exercise 2.11 cosh −𝑥 = 𝑐𝑜𝑠ℎ𝑥 Prove the Following Hyperbolic Functions sinh −𝑥 = −𝑠𝑖𝑛ℎ𝑥 𝑐𝑜𝑠ℎ𝑥 + 𝑠𝑖𝑛ℎ𝑥 = 𝑒𝑥 𝑐𝑜𝑠ℎ𝑥 − 𝑠𝑖𝑛ℎ𝑥 = 𝑒−𝑥 coth2 𝑥 − 1 = csch2 𝑥 sinh 𝑥 ± 𝑦 = 𝑠𝑖𝑛ℎ𝑥𝑐𝑜𝑠ℎ𝑦 ± 𝑐𝑜𝑠ℎ𝑥𝑠𝑖𝑛ℎ𝑦 cosh 𝑥 ± 𝑦 = 𝑐𝑜𝑠ℎ𝑥𝑐𝑜𝑠ℎ𝑦 ± 𝑠𝑖𝑛ℎ𝑥𝑠𝑖𝑛ℎ𝑦 tanh 𝑙𝑛𝑥 = 𝑥2 − 1 𝑥2 + 1 1 + 𝑡𝑎𝑛ℎ𝑥 1 − 𝑡𝑎𝑛ℎ𝑥 = 𝑒2𝑥
  • 74. Assignment 2.1 2.1.1. 𝑦 = 𝑥2 + 6𝑥 − 8 2.1.2. 𝑦 = 7 + 2𝑥 − 𝑥2 2.1.3. 𝑦 = 2𝑥 + 5 2.1.4. 𝑦 = 2𝑥 + 5 2.1.5. 𝑦 = 2 − 𝑥 + 3 2.1.6. 𝑦 = 3 x+2 2.1.7. 𝑦 = 𝑥−4 2𝑥+3 2.1.8. 𝑦 = −2 − 4𝑥 − 𝑥2 2.1.9. 𝑦 = −𝑠𝑖𝑛2𝑥 2.1.10. 𝑦 = 1 2 1 + 𝑒𝑥 2.1.11. 𝑓 𝑥 = 1 𝑥+2 2.1.12. 𝑓 𝑥 = 5𝑥+1 + 2 2.1.13. 𝑓 𝑥 = 3 + 𝑙𝑛𝑥 2.1.14. 𝑓 𝑥 = ln 𝑥 − 1 2.1.15. 𝑓 𝑥 = 𝑙𝑜𝑔𝑥 − 1 2.1.16. 𝑓 𝑥 = ln −𝑥 2.1.17. 𝑓 𝑥 = 𝑒𝑥 + 2 2.1.18. 𝑓 𝑥 = 𝑒−𝑥 − 1 2.1.19. 𝑓 𝑥 = 4 cos 2𝑥 − 𝜋 2 2.1.20. 𝑓 𝑥 = −3sin(𝜋𝑥 + 2) 74 Graph each of the following functions then from the graph find its the domain and range.