Calculus 1
Calculus 1
Calculus (I)!
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df(x) N0-4ac N 62-4a0
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x+ +
2a 2a 2a
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x• • f(x)
a• bo • f(a) = f(b)
Domain Range
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a
4
3
Domain
1 !
1-
DEFINITION Afunction f from a set Dot a set Ysi a rule that assigns a unique
value f(x) in Yto each x in D
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Two Important Symbols and The Definition of Function
1 V For any
2 3 Exist
Two y values for one value Two times for one temperature
of x fails test—not a function a—function
Temperature
Vertical Line Test
A graph represents a function if and only if ti passes the vertical line test: Every
vertical line intersects the graph at most once. A graph that fails this test does not
represent a function.
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Function
• f(x) read "fofx" or "fat x", denotes the value that f assigns ot .x
Example 1
f(x + )h - f(x)
f(x) -
Soluti on:
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Natural
d o m a i no f Funocitn
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The graphics of functions
(-2, 4) 41
(2, 4)
2- 4 y = 2x
3
1-
0 0 2- 2( %
)
1 1 (-1, 1) a • (1,1)
914
3 12
→X
-1 1 2
2 4 Graph of the function
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The graphics of functions
Pressure
P (pressure uPa)
Time Pressure Tm
ie
0.00091
0.00108
-0.080
0.200
0.00362
0.00379
02.17
0.480
01. - • Data
0.00125 0.480 0.00398 06.81
0.00144 06.93 0.00416 08.10
00.0162 08.16 0.00435 08.27
00.0180 0.844 00.0453 07.49
00.0198 0. 00.0471 05.81 -0 .2 -
00.01 00.02 0.003/ 0.004 00.05 00,06 →t (sec)
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The graphics of functions
Graph of a catenary or
hanging cable. (The Latin word catena
means "chain.") 13/60
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The graphics of functions
A
Y
y = x- y = f(x)
-3
1
y= 1
2 ifx<1
g(x) = 0 if1 < x < 2
1- fi x > 2 2- 0 2 →x
-1 3
To graph the
- |1
function y= f(x) shown here,
we apply different formulas ot
different parts of its domain
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У 11 = 50
8
Area = A(5)
Aera = A2()
5
-4
3 02
A 81
16 i f > 3
8-
41
y= J y=/( 12
5 6 7 8 01
The graphics of some important functions
Range: y>0
y = loga x
y = log3x
→x
y= logs.x
y = log10x
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y=
/ 2x + 2 Add a positive Add a negative
= +1 constant to .x constant to .x
2
2
(* +3 ) = x y =(
* 2)
~
1 unit -
→
2-
2 units 3- →x
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y = /x|
y = - x 4 y=/x-2|-1
2
1
-2 1- 1 2 3 >x - 4 2-
- 1
4 6 →x
→stretch
y=V* 3 -2 4
compres fy=Vx y = Vx/3 -1|
2 3 Vx
FIGURE Vertically stretching and FIGURE Horizontally stretching and FIGURE Reflections of the graph
compressing the graph y = Vx by a
factor of 3 riyb afactor fo
compressing hte graph y= V y = Vr across hte coordinate axes
The graphics of functions
Vertical stretch or compression; •Vertical shift
reflection about sxai- if negative
y = af(b(x + c)) + d
Horizontal stretch or compression; Horizontal shift
reflection aboutsayx-i if negative
- 1 )
- 2
The graph fo y = f(x - )b is the graph For c >0, the graph of y = cf(x) si the graph For c< Q,the phagr of y= ef(x) ishet graph
of roF a < 0, the graph of y = f(ax) si the graph of y = x()f
of
y = f(x) shifted horizontally yb b units of y = f(x) sealed vertically by a factor of c y = f(x) scaled vertically yb a factor of k and scaled horizontally yb a factor of(a)and reflected acors the
(right fi b > 0and left fi b < .)0
(broadened fi 0 < c < 1 and steepened fi c > I). reflected across hte x-axsi (broadened fi ya'xis (broadened fi - 1< a< 0 nda steepened fi a< - 1).
y = f(x)
(
- 2x)
= f(x)
(x 2)
3/x)
—xY y = - ( 0)
y = 2/(x)
/(x)
2)-y=
({
y= 2x-(f)
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Given the real numbers a, b, c, and d and the function f, the graph of
y = cf(ax - b)) + d si obtained from the graph of y = f(x) ni the
following steps.
horizontal scaling
by a factor o f a
y = f(x) →y = f(ax)
horizontal shift
by b units
→y = f(ax - b))
vertical scaling
by a factor of cl
→y = cf(ax - b))
vertical shift
by d units
→y = cf(ax - b)) + d
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Basic curve
2- ½
-1
=2 x +
1]
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Monotonic Functions
h h = 30t - 517
Downward
- 40-
ground (meters)
path of
Height above
30 the stone
Upward 20
path of
the stone 10
0 5 6
m
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Even a n d Odd Functions
If the domain of the function f(x) is symmetric with respect to 0, and
Symmetry (-x, y)
about y-axis
Symmetry
about origin
/(
.y)
V x, f (
- x)
= / (
x),
(-x, y-)
→ f(x) is an Odd Function
(b)
The graphs of odd function si symmetre with respect ot the origin of coordinate (0,0)
Even a n d Odd Functions
20
( - 0 . 5 . 2.67)
01 -
10-
(1.5, 0.53)
_⺾
wta
(-1.5. -0.53)
- 10-
(-2, - 12) (2, - 12) 1
(0.5, - 2.67)
⼀ 10 ⼀ y= x - +x3
y =x*
- 2x2 - 20
3-0-
02- -
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Inverse F u n c t i o n s
DEFINITION Inverse Function
Given a function ,f its inverse (if ti exists) si a function f*' such that whenever
y= f(x), then f'( y) = r
x is in the domain of fand
* =f'(y) si ni hte range off! Two values of x
correspond to y.
m
faps r toy (x. y)
y =/(x)
x(. y)
• y = f(x)
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Inverse F u n c t i o n s
DEFN
IT
IO
IN One-to-One Functions and the Horizontal Line Test
A function f is one-to-one on a domain D fi each value of f(x) corresponds to exactly
one value of xni D. More precisely, f si one-to-one on D if f(x,) # f(x2) whenever
x, # X2, for x, and zx ni D. The horizontal line test says that every horizontal line
intersects the graph of a one-to-one function at most once
One-to-one function:
Each value of y ni the range Not one-to-one function:
corresponds ot exactly Some values of y correspond
one value fo .x to more than one value of.x.
Y
A
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Inverse Functions
ffails hte
horizontal
line test.
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Inverse Functions
DOMA
N
I OFf RANGE FO f-'
a)( To find the value of fat x,w e start at ,x (b) The graph of f-' si hte gaprh of f.but
(e)oT darw the garph of f"' in the )d( nehT ew interchange eht eltxrs. dna y.
go up ot the curve, and then over ot the y-axis. with x and y interchanged. oT find the x that more usual way, we reflect the eW now evah a norma-looknig garph off
gave y, we start at y and go over to the curve
and down to hte x-axis. The domain of f i s hte
range off. The range of f ' si het domain of .f
FIGURE The graph ofy = f*'(x) is obtained yb reflecting the graph ofy = f(x)
about the nile y = .x
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Inverse Functions
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Inverse F u n c t i o n s
PROCEDURE Finding an Inverse Function
Suppose f is one-to-one on an interval I. To find f ' :
.1 Solve y = f(x) for x. fI necessary, choose hte function that corresponds ot .I
2. Interchange xand y and write y= f(x).
y=f*'(x) = Vx+ 1+
V
x
↓— ⼗
+ y =5'(x) = - Vx+1
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Inverse F u n c t i o n s
y = X
f(x) = 2x + 6
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Inverse F u n c t i o n s
DEFINITION Logarithmic Function Base b
For any base b > 0, with b # 1, the logarithmic function base b, denoted y = log, x,
is the inverse of the exponential function y= b*. The inverse of the natural exponential
function with base b = e si the natural logarithm function, denoted y = In x.
y = e*
Graphs of b* and log, x are
symmetric about y = x.
= 、b > 1 y = 2*
5
y= x
y =x
eo< (1, e)
y = In x
(O, 1) y = log, * y = log2x
2 > x 4
(, )0
(b)
(a)
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Inverse Functions
nI x= y → e = .x
In e = 1.
Inverse Functions
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Inverse F u n c t i o n s
Change-of-Base Rules
Let b be a positive real number with b * .1 Then
In x
b* = e*Inb, for all x and 10g, x = nI b' forx > 0.
More generally, fi c is a positive real number with c # ,1 then
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Inverse F u n c t i o n s
THEOREM Existence of Inverse Functions
Let f be a one-to-one function on a domain D with a range R
. Then f has a unique
inverse f ' with domain Rand range D such that
f'(f(x)) = x and f f ' (y)) = ,y
where x is in D and y is in R.
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Operations on Functions
8/f 8((xx))
(x) = 7 =V (0, 1] (x = 0 excluder
> x
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Composite Functions
Function Function
8
→ I = g(r) → →y = f u ) = f(g(x))
(a)
• f(g(x,)
Composite Functions
DEFINITION fI fand g are functions, the composite function f • g ("f com-
posed with g") si defined by
(f ° g)(x) = f(g(x)).
The domain of f• g consists of hte numbers xni hte domain of g for which g(x)
lies ni the domain of f
fog
D
o f(g(x))
x → 8 g(x) f → f(g(x))
Composite Functions
Composition of g with f is defined as follows
(gof)(x) = g ( f ( x ) )
the domain of g o f is
(I) x is in the domain o f g
(2) f(x) is in the domain of g
C
8
y=f(x)
* g(V)=g((x))=gof(x)
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Composite Functions 多
У
9
اﻟﺴﻨﺎ
8
f (g(5)) = ?
7
6
5
g(f (5)) ?=
2 8(
1)
⽞
17
9
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Terminal ray>
Initial ray
→x
Positive Initial ray
Negative
measure Terminal measure
→x
ray y
砍- →x
Nonzero radian measures can be positive or negative and can go beyond 2mr.
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Trigonometric Functions and Their Inverses
(O.)1
(-⼩吆) (6-2) 43()
(- . )
( -; ) (4.23)
°021
45 *m/3
/4
=
m
6-0
( - . ) 150P ( . ))
3=/2
1-3
m°
-
357°
伊- 脂 5=
/4
/6
18 0°m a 0 ° = 0 radians
(-I.0)Ф • (10.)|
360° - 2=
/4
- 617
0- 噌 3 30
Sw
210° °-
11.
3=/2|
-2-1 66 7(7-1
315° 0S°#/3
3A
-
/
%
°52
7
3-0
240° -
A4
( .- ) (½. - )
270° -
(4-2) (½. - )
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hypotenuse
opposite cot 0 =
P(r, y)
adjacent
sin 0= OP
hyp
csc 0=hyp x
opp
cos @=ahydpi sec o= hadj
yp
Opp
tan 0= adj cot o= aOPP
dj
FIGURE Trigonometric Apositive angle 0 results from
a counterclock wsie rotation.
ratios of an acute angle.
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The graphs of y= sin 0 and its reciprocal, y= csc 0 The graphs of y= cos 0 and its reciprocal, y= sec 0
= s e c0
y = c s c0
= sin 0
y = cos 0
3m Mm 2 3 тЛт 4
3?
2
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Trigonometric Functions and Their Inverses
y = tan 0 y = cot 0
Вт 2 m
S 3т 4m
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D om ai n: - ∞ < x <8
Range: -1sys1
Domain: — 00 < x < 00|
Range: - 1s y s 1
Domain: x*场 ⼟贺
Range: - 0 < y<00
Period: 2 Period: 2
Period:
(a) (b) (c)
=C
S
Cx
2m
-
FIGURE Graphs of the six basic trigonometric functions using radian measure. The shading for each 48/60
trigonometric function indicates its periodicity.
Trigonometric Functions and Their Inverses
Trigonometric Identities
Periods of Trigonometric Functions Reciprocal Identities
Period n : tan (x + mr) = tanx COs 0
cot (x + m) = cotx atn ®= sni 0 cot 0 =
1
=
Cos e tan 0 sin 0
Period 2m: sin (x + 2mr) = sin x 1 1
cos (x + 2m) = cos x C
S
C 0= sec 0 =
sin 0 COS 0
sec (x + 2m) = sec x
csc (x + 2m) = esc x Pythagorean Identities
sin? 0 + cos?0 = 1 1 + cot 0 = csc? 0 tan 2e + 1 = s ec ' e
sin x
cosx
csex
y= sin.x
y = cos x
1
Domain = | - ₴
D om ai n = [0, m)
y = sin.
[0 . m ]
(x, y)
V2/2 =/ 4
Cos 0 = x
0= c o s ' x 1/2 тт / 6 п/3
- 1/2 - 7/ 6 2 / 3
- V2/2 - /4 3 / 4
- V3/2 - тт/3 5т / 6
arccos x
Taercos )2 -72
V3 T
arcsin x
→ x
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Trigonometric Functions and Their Inverses
y= c o t 'x
Range of tan x' Range of cot 'x
y = tan ' x
si (- ₴.) si (0, m.)
- 11
y = cot x
Restricted domain
y= x of cot x is (0, m.)
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Trigonome tric Functions a n d Their Inverses
y= csex
see x y= x
Range of c s c r
sec x Range of es x'
i sT
0. a】y *sh.
-1
k/cr
y = sec.x Csc I x -1 Restricted domain of
Restricted domain of
sec.ris (0, #).x # = 2
y = csc x
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V 1 + x2
x
tan 0 = x →=
• = tan' x
[
1
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Trigonome tric Functions and Their Inverses
Domain: 1- Sx s 1 Domain: 1-5 x≤ 1 Domain: - 00 < x < oc
Range: - 2S y s " Range: Osys n Range:
→
x
y= arcsec x
Ty = acrese * y = arccotx
H o m e w o r k 1: