Harold's Calculus Notes Cheat Sheet AP Calculus Limits

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Harold’s Calculus Notes
Cheat Sheet
15 December 2015
AP Calculus
Limits
Definition of Limit
Let f be a function defined on an open
interval containing c and let L be a real
number. The statement:
lim 𝑓(π‘₯) = 𝐿
π‘₯→π‘Ž
means that for each πœ– > 0 there exists a
𝛿 > 0 such that
if 0 < |π‘₯ − π‘Ž| < 𝛿, then |𝑓(π‘₯) − 𝐿| < πœ–
Tip :
Direct substitution: Plug in 𝑓(π‘Ž) and see if
it provides a legal answer. If so then L =
𝑓(π‘Ž).
The Existence of a Limit
The limit of 𝑓(π‘₯) as π‘₯ approaches a is L if
and only if:
lim 𝑓(π‘₯) = 𝐿
π‘₯→π‘Ž −
lim 𝑓(π‘₯) = 𝐿
π‘₯→π‘Ž +
𝟐
Prove that 𝒇(𝒙) = 𝒙 − 𝟏 is a continuous function.
Definition of Continuity
A function f is continuous at c if for
every πœ€ > 0 there exists a 𝛿 > 0 such that
|π‘₯ − 𝑐| < 𝛿 and |𝑓(π‘₯) − 𝑓(𝑐)| < πœ€.
Tip: Rearrange |𝑓(π‘₯) − 𝑓(𝑐)| to have
|(π‘₯ − 𝑐)| as a factor. Since |π‘₯ − 𝑐| < 𝛿 we
can find an equation that relates both 𝛿
and πœ€ together.
|𝑓(π‘₯) − 𝑓(𝑐)|
= |(π‘₯ 2 − 1) − (𝑐 2 − 1)|
= |π‘₯ 2 − 1 − 𝑐 2 + 1|
= |π‘₯ 2 − 𝑐 2 |
= |(π‘₯ + 𝑐)(π‘₯ − 𝑐)|
= |(π‘₯ + 𝑐)| |(π‘₯ − 𝑐)|
Since |(π‘₯ + 𝑐)| ≤ |2𝑐|
|𝑓(π‘₯) − 𝑓(𝑐)| ≤ |2𝑐||(π‘₯ − 𝑐)| < πœ€
𝟏
So given πœ€ > 0, we can choose 𝜹 = |πŸπ’„| 𝜺 > 𝟎 in the
Definition of Continuity. So substituting the chosen 𝛿
for |(π‘₯ − 𝑐)| we get:
1
|𝑓(π‘₯) − 𝑓(𝑐)| ≤ |2𝑐| (| | πœ€) = πœ€
2𝑐
Since both conditions are met, 𝑓(π‘₯) is continuous.
𝑠𝑖𝑛 π‘₯
=1
π‘₯→0 π‘₯
π‘™π‘–π‘š
Two Special Trig Limits
1 − π‘π‘œπ‘  π‘₯
=0
π‘₯→0
π‘₯
π‘™π‘–π‘š
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
1
Derivatives
Definition of a Derivative of a Function
Slope Function
Notation for Derivatives
The Constant Rule
The Power Rule
The General Power Rule
The Constant Multiple Rule
The Sum and Difference Rule
Position Function
Velocity Function
Acceleration Function
Jerk Function
The Product Rule
The Quotient Rule
The Chain Rule
Exponentials (𝒆𝒙 , 𝒂𝒙 )
Logorithms (π₯𝐧 𝒙 , π₯𝐨𝐠 𝒂 𝒙)
Sine
Cosine
Tangent
Secent
Cosecent
Cotangent
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
(See Larson’s 1-pager of common derivatives)
𝑓(π‘₯ + β„Ž) − 𝑓(π‘₯)
𝑓 ′ (π‘₯) = lim
β„Ž→0
β„Ž
𝑓(π‘₯) − 𝑓(𝑐)
π‘₯→𝑐
π‘₯−𝑐
𝑑𝑦 ′ 𝑑
′ (π‘₯), (𝑛) (π‘₯),
𝑓
𝑓
, 𝑦 , [𝑓(π‘₯)], 𝐷π‘₯ [𝑦]
𝑑π‘₯
𝑑π‘₯
𝑑
[𝑐] = 0
𝑑π‘₯
𝑑 𝑛
[π‘₯ ] = 𝑛π‘₯ 𝑛−1
𝑑π‘₯
𝑑
[π‘₯] = 1 (π‘‘β„Žπ‘–π‘›π‘˜ π‘₯ = π‘₯ 1 π‘Žπ‘›π‘‘ π‘₯ 0 = 1)
𝑑π‘₯
𝑑 𝑛
[𝑒 ] = 𝑛𝑒𝑛−1 𝑒′ π‘€β„Žπ‘’π‘Ÿπ‘’ 𝑒 = 𝑒(π‘₯)
𝑑π‘₯
𝑑
[𝑐𝑓(π‘₯)] = 𝑐𝑓 ′ (π‘₯)
𝑑π‘₯
𝑑
[𝑓(π‘₯) ± 𝑔(π‘₯)] = 𝑓 ′ (π‘₯) ± 𝑔′ (π‘₯)
𝑑π‘₯
1
𝑠(𝑑) = 𝑔𝑑 2 + 𝑣0 𝑑 + 𝑠0
2
𝑣(𝑑) = 𝑠 ′ (𝑑) = 𝑔𝑑 + 𝑣0
π‘Ž(𝑑) = 𝑣 ′ (𝑑) = 𝑠 ′′ (𝑑)
𝑗(𝑑) = π‘Ž′ (𝑑) = 𝑣 ′′ (𝑑) = 𝑠 (3) (𝑑)
𝑑
[𝑓𝑔] = 𝑓𝑔′ + 𝑔 𝑓 ′
𝑑π‘₯
𝑑 𝑓
𝑔𝑓 ′ − 𝑓𝑔′
[ ]=
𝑑π‘₯ 𝑔
𝑔2
𝑑
[𝑓(𝑔(π‘₯))] = 𝑓 ′ (𝑔(π‘₯))𝑔′ (π‘₯)
𝑑π‘₯
𝑑𝑦 𝑑𝑦 𝑑𝑒
=
·
𝑑π‘₯ 𝑑𝑒 𝑑π‘₯
𝑑 π‘₯
𝑑 π‘₯
[𝑒 ] = 𝑒 π‘₯ ,
[π‘Ž ] = (ln π‘Ž) π‘Ž π‘₯
𝑑π‘₯
𝑑π‘₯
𝑑
1
𝑑
1
[ln π‘₯] = ,
[log π‘Ž π‘₯] =
𝑑π‘₯
π‘₯
𝑑π‘₯
(ln π‘Ž) π‘₯
𝑑
[𝑠𝑖𝑛(π‘₯)] = cos(π‘₯)
𝑑π‘₯
𝑑
[π‘π‘œπ‘ (π‘₯)] = −𝑠𝑖𝑛(π‘₯)
𝑑π‘₯
𝑑
[π‘‘π‘Žπ‘›(π‘₯)] = 𝑠𝑒𝑐 2(π‘₯)
𝑑π‘₯
𝑑
[𝑠𝑒𝑐(π‘₯)] = 𝑠𝑒𝑐(π‘₯) π‘‘π‘Žπ‘›(π‘₯)
𝑑π‘₯
𝑑
[𝑐𝑠𝑐(π‘₯)] = − 𝑐𝑠𝑐(π‘₯) π‘π‘œπ‘‘(π‘₯)
𝑑π‘₯
𝑑
[π‘π‘œπ‘‘(π‘₯)] = −𝑐𝑠𝑐 2 (π‘₯)
𝑑π‘₯
𝑓 ′ (𝑐) = lim
2
Applications of Differentiation
Rolle’s Theorem
f is continuous on the closed interval [a,b],
and
f is differentiable on the open interval (a,b).
If f(a) = f(b), then there exists at least one number c in
(a,b) such that f’(c) = 0.
𝑓(𝑏) − 𝑓(π‘Ž)
𝑏−π‘Ž
𝑓(𝑏) = 𝑓(π‘Ž) + (𝑏 − π‘Ž)𝑓′(𝑐)
Find ‘c’.
𝑃(π‘₯)
𝐼𝑓 lim 𝑓(π‘₯) = lim
=
π‘₯→𝑐
π‘₯→𝑐 𝑄(π‘₯)
Mean Value Theorem
If f meets the conditions of Rolle’s
Theorem, then
𝑓 ′ (𝑐) =
0 ∞
{ , , 0 • ∞, 1∞ , 00 , ∞0 , ∞ − ∞} , 𝑏𝑒𝑑 π‘›π‘œπ‘‘ {0∞ },
0 ∞
𝑃(π‘₯)
𝑃′ (π‘₯)
𝑃′′ (π‘₯)
π‘‘β„Žπ‘’π‘› lim
= lim ′
= lim ′′
=β‹―
π‘₯→𝑐 𝑄(π‘₯)
π‘₯→𝑐 𝑄 (π‘₯)
π‘₯→𝑐 𝑄 (π‘₯)
L’Hôpital’s Rule
Graphing with Derivatives
Test for Increasing and Decreasing
Functions
The First Derivative Test
The Second Deriviative Test
Let f ’(c)=0, and f ”(x) exists, then
Test for Concavity
Points of Inflection
Change in concavity
Analyzing the Graph of a
Function
1. If f ’(x) > 0, then f is increasing (slope up) β†—
2. If f ’(x) < 0, then f is decreasing (slope down) β†˜
3. If f ’(x) = 0, then f is constant (zero slope) →
1. If f ’(x) changes from – to + at c, then f has a relative
minimum at (c, f(c))
2. If f ’(x) changes from + to - at c, then f has a relative
maximum at (c, f(c))
3. If f ’(x), is + c + or - c -, then f(c) is neither
1. If f ”(x) > 0, then f has a relative minimum at (c, f(c))
2. If f ”(x) < 0, then f has a relative maximum at (c, f(c))
3. If f ’(x) = 0, then the test fails (See 1𝑠𝑑 derivative test)
1. If f ”(x) > 0 for all x, then the graph is concave up ⋃
2. If f ”(x) < 0 for all x, then the graph is concave down β‹‚
If (c, f(c)) is a point of inflection of f, then either
1. f ”(c) = 0 or
2. f ” does not exist at x = c.
(See Harold’s Illegals and Graphing Rationals Cheat
Sheet)
x-Intercepts (Zeros or Roots)
y-Intercept
Domain
Range
Continuity
Vertical Asymptotes (VA)
Horizontal Asymptotes (HA)
Infinite Limits at Infinity
Differentiability
Relative Extrema
Concavity
Points of Inflection
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
f(x) = 0
f(0) = y
Valid x values
Valid y values
No division by 0, no negative square roots or logs
x = division by 0 or undefined
lim− 𝑓(π‘₯) → 𝑦 and lim+ 𝑓(π‘₯) → 𝑦
π‘₯→∞
π‘₯→∞
lim− 𝑓(π‘₯) → ∞ and lim+ 𝑓(π‘₯) → ∞
π‘₯→∞
π‘₯→∞
Limit from both directions arrives at the same slope
Create a table with domains, f(x), f ’(x), and f ”(x)
If 𝑓 ”(π‘₯) → +, then cup up ⋃
If 𝑓 ”(π‘₯) → −, then cup down β‹‚
f ”(x) = 0 (concavity changes)
3
Approximating with
Differentials
𝑓(π‘₯𝑛 )
𝑓′(π‘₯𝑛 )
𝑦 = π‘šπ‘₯ + 𝑏
𝑦 = 𝑓 ′ (𝑐)(π‘₯ − 𝑐) + 𝑓(𝑐)
Newton’s Method
Finds zeros of f, or finds c if f(c) = 0.
π‘₯𝑛+1 = π‘₯𝑛 −
Tangent Line Approximations
Function Approximations with
Differentials
Related Rates
𝑓(π‘₯ + βˆ†π‘₯) ≈ 𝑓(π‘₯) + 𝑑𝑦 = 𝑓(π‘₯) + 𝑓 ′ (π‘₯) 𝑑π‘₯
Steps to solve:
1. Identify the known variables and rates of change.
π‘š
(π‘₯ = 2 π‘š; 𝑦 = −3 π‘š; π‘₯ ′ = 4 ; 𝑦 ′ = ? )
𝑠
2. Construct an equation relating these quantities.
(π‘₯ 2 + 𝑦 2 = π‘Ÿ 2 )
3. Differentiate both sides of the equation.
(2π‘₯π‘₯ ′ + 2𝑦𝑦 ′ = 0)
4. Solve for the desired rate of change.
π‘₯
(𝑦 ′ = − π‘₯ ′ )
𝑦
5. Substitute the known rates of change and quantities
into the equation.
2
8π‘š
(𝑦 ′ = −
⦁4=
)
−3
3 𝑠
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
4
Integration
∫ 𝑓 ′ (π‘₯) 𝑑π‘₯ = 𝑓(π‘₯) + 𝐢
Basic Integration Rules
Integration is the “inverse” of
differentiation, and vice versa.
𝑑
∫ 𝑓(π‘₯) 𝑑π‘₯ = 𝑓(π‘₯)
𝑑π‘₯
𝑓(π‘₯) = 0
∫ 0 𝑑π‘₯ = 𝐢
𝑓(π‘₯) = π‘˜ = π‘˜π‘₯ 0
∫ π‘˜ 𝑑π‘₯ = π‘˜π‘₯ + 𝐢
The Constant Multiple Rule
∫ π‘˜ 𝑓(π‘₯) 𝑑π‘₯ = π‘˜ ∫ 𝑓(π‘₯) 𝑑π‘₯
The Sum and Difference Rule
∫[𝑓(π‘₯) ± 𝑔(π‘₯)] 𝑑π‘₯ = ∫ 𝑓(π‘₯) 𝑑π‘₯ ± ∫ 𝑔(π‘₯) 𝑑π‘₯
∫ π‘₯ 𝑛 𝑑π‘₯ =
The Power Rule
𝑓(π‘₯) = π‘˜π‘₯ 𝑛
π‘₯ 𝑛+1
+ 𝐢, π‘€β„Žπ‘’π‘Ÿπ‘’ 𝑛 ≠ −1
𝑛+1
𝐼𝑓 𝑛 = −1, π‘‘β„Žπ‘’π‘› ∫ π‘₯ −1 𝑑π‘₯ = ln|π‘₯| + 𝐢
𝑑
If 𝑒 = 𝑔(π‘₯), π‘Žπ‘›π‘‘ 𝑒′ = 𝑔(π‘₯) then
𝑑π‘₯
𝑒𝑛+1
𝑛 ′
∫ 𝑒 𝑒 𝑑π‘₯ =
+ 𝐢, π‘€β„Žπ‘’π‘Ÿπ‘’ 𝑛 ≠ −1
𝑛+1
The General Power Rule
𝑛
∑ 𝑓(𝑐𝑖 ) βˆ†π‘₯𝑖 ,
Reimann Sum
π‘€β„Žπ‘’π‘Ÿπ‘’ π‘₯𝑖−1 ≤ 𝑐𝑖 ≤ π‘₯𝑖
𝑖=1
β€–βˆ†β€– = βˆ†π‘₯ =
𝑛
Definition of a Definite Integral
Area under curve
𝑏−π‘Ž
𝑛
𝑏
lim ∑ 𝑓(𝑐𝑖 ) βˆ†π‘₯𝑖 = ∫ 𝑓(π‘₯) 𝑑π‘₯
β€–βˆ†β€–→0
𝑏
Swap Bounds
π‘Ž
𝑖=1
π‘Ž
∫ 𝑓(π‘₯) 𝑑π‘₯ = − ∫ 𝑓(π‘₯) 𝑑π‘₯
π‘Ž
𝑏
Additive Interval Property
𝑐
𝑏
𝑏
∫ 𝑓(π‘₯) 𝑑π‘₯ = ∫ 𝑓(π‘₯) 𝑑π‘₯ + ∫ 𝑓(π‘₯) 𝑑π‘₯
π‘Ž
π‘Ž
𝑏
The Fundamental Theorem of
Calculus
𝑐
∫ 𝑓(π‘₯) 𝑑π‘₯ = 𝐹(𝑏) − 𝐹(π‘Ž)
π‘Ž
π‘₯
𝑑
∫ 𝑓(𝑑) 𝑑𝑑 = 𝑓(π‘₯)
𝑑π‘₯
𝑔(π‘₯)
The Second Fundamental
Theorem of Calculus
𝑑
∫ 𝑓(𝑑) 𝑑𝑑 = 𝑓(𝑔(π‘₯))𝑔′ (π‘₯)
𝑑π‘₯
π‘Ž
β„Ž(π‘₯)
(See Harold’s Fundamental
Theorem of Calculus Cheat Sheet)
π‘Ž
𝑑
∫ 𝑓(𝑑) 𝑑𝑑 = 𝑓(β„Ž(π‘₯))β„Ž′ (π‘₯) − 𝑓(𝑔(π‘₯))𝑔′(π‘₯)
𝑑π‘₯
Mean Value Theorem for
Integrals
The Average Value for a
Function
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
𝑔(π‘₯)
𝑏
∫ 𝑓(π‘₯) 𝑑π‘₯ = 𝑓(𝑐)(𝑏 − π‘Ž) Find ‘𝑐’.
π‘Ž
𝑏
1
∫ 𝑓(π‘₯) 𝑑π‘₯
𝑏−π‘Ž π‘Ž
5
Summation Formulas
𝑛
∑ 𝑐 = 𝑐𝑛
𝑖=1
𝑛
∑𝑖 =
𝑖=1
𝑛
𝑛(𝑛 + 1) 𝑛2 𝑛
=
+
2
2 2
∑ 𝑖2 =
𝑖=1
𝑛
𝑛(𝑛 + 1)(2𝑛 + 1) 𝑛3 𝑛2 𝑛
=
+ +
6
3
2 6
2
𝑛
3
∑ 𝑖 = (∑ 𝑖 ) =
𝑖=1
𝑛
Sum of Powers
𝑖=1
𝑛2 (𝑛 + 1)2 𝑛4 𝑛3 𝑛2
=
+ +
4
4
2
4
𝑛(𝑛 + 1)(2𝑛 + 1)(3𝑛2 + 3𝑛 − 1) 𝑛5 𝑛4 𝑛3 𝑛
∑ 𝑖4 =
=
+ + −
30
5
2
3 30
𝑖=1
𝑛
∑ 𝑖5 =
𝑖=1
𝑛
∑ 𝑖6 =
𝑖=1
𝑛
∑ 𝑖7 =
𝑖=1
𝑛2 (𝑛 + 1)2 (2𝑛2 + 2𝑛 − 1) 𝑛6 𝑛5 5𝑛4 𝑛2
=
+ +
−
12
6
2
12 12
𝑛(𝑛 + 1)(2𝑛 + 1)(3𝑛4 + 6𝑛3 − 3𝑛 + 1)
42
𝑛2 (𝑛 + 1)2 (3𝑛4 + 6𝑛3 − 𝑛2 − 4𝑛 + 2)
24
𝑛
π‘˜−1
(𝑛 + 1)π‘˜+1
1
π‘˜+1
π‘†π‘˜ (𝑛) = ∑ 𝑖 =
−
∑(
) π‘†π‘Ÿ (𝑛)
π‘˜+1
π‘˜+1
π‘Ÿ
π‘˜
𝑖=1
𝑛
π‘Ÿ=0
𝑛
𝑛
2
∑ 𝑖(𝑖 + 1) = ∑ 𝑖 + ∑ 𝑖 =
𝑖=1
𝑛
Misc. Summation Formulas
𝑖=1
𝑖=1
𝑛(𝑛 + 1)(𝑛 + 2)
3
1
𝑛
∑
=
𝑖(𝑖 + 1) 𝑛 + 1
𝑖=1
𝑛
∑
𝑖=1
1
𝑛(𝑛 + 3)
=
𝑖(𝑖 + 1)(𝑖 + 2) 4(𝑛 + 1)(𝑛 + 2)
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
6
Integration Methods
1. Memorized
See Larson’s 1-pager of common integrals
∫ 𝑓(𝑔(π‘₯))𝑔′ (π‘₯)𝑑π‘₯ = 𝐹(𝑔(π‘₯)) + 𝐢
2. U-Substitution
Set 𝑒 = 𝑔(π‘₯), then 𝑑𝑒 = 𝑔′ (π‘₯) 𝑑π‘₯
∫ 𝑓(𝑒) 𝑑𝑒 = 𝐹(𝑒) + 𝐢
𝑒 = _____
𝑑𝑒 = _____ 𝑑π‘₯
∫ 𝑒 𝑑𝑣 = 𝑒𝑣 − ∫ 𝑣 𝑑𝑒
𝑒 = _____
𝑑𝑒 = _____
3. Integration by Parts
4. Partial Fractions
𝑣 = _____
𝑑𝑣 = _____
Pick ‘𝑒’ using the LIATED Rule:
L – Logarithmic : ln π‘₯ , log 𝑏 π‘₯ , 𝑒𝑑𝑐.
I – Inverse Trig.:
tan−1 π‘₯ , sec −1 π‘₯ , 𝑒𝑑𝑐.
A – Algebraic:
π‘₯ 2 , 3π‘₯ 60 , 𝑒𝑑𝑐.
T – Trigonometric: sin π‘₯ , tan π‘₯ , 𝑒𝑑𝑐.
E – Exponential:
𝑒 π‘₯ , 19π‘₯ , 𝑒𝑑𝑐.
D – Derivative of: 𝑑𝑦⁄𝑑π‘₯
𝑃(π‘₯)
∫
𝑑π‘₯
𝑄(π‘₯)
where 𝑃(π‘₯) π‘Žπ‘›π‘‘ 𝑄(π‘₯) are polynomials
Case 1: If degree of 𝑃(π‘₯) ≥ 𝑄(π‘₯)
then do long division first
Case 2: If degree of 𝑃(π‘₯) < 𝑄(π‘₯)
then do partial fraction expansion
∫ √π‘Ž2 − π‘₯ 2 𝑑π‘₯
5a. Trig Substitution for √π’‚πŸ − π’™πŸ
Substutution: π‘₯ = π‘Ž sin πœƒ
Identity: 1 − 𝑠𝑖𝑛2 πœƒ = π‘π‘œπ‘  2 πœƒ
∫ √π‘₯ 2 − π‘Ž2 𝑑π‘₯
5b. Trig Substitution for √π’™πŸ − π’‚πŸ
Substutution: π‘₯ = π‘Ž sec πœƒ
Identity: 𝑠𝑒𝑐 2 πœƒ − 1 = π‘‘π‘Žπ‘›2 πœƒ
∫ √π‘₯ 2 + π‘Ž2 𝑑π‘₯
5c. Trig Substitution for √π’™πŸ + π’‚πŸ
6. Table of Integrals
7. Computer Algebra Systems (CAS)
8. Numerical Methods
9. WolframAlpha
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
Substutution: π‘₯ = π‘Ž tan πœƒ
Identity: π‘‘π‘Žπ‘›2 πœƒ + 1 = 𝑠𝑒𝑐 2 πœƒ
CRC Standard Mathematical Tables book
TI-Nspire CX CAS Graphing Calculator
TI –Nspire CAS iPad app
Riemann Sum, Midpoint Rule, Trapezoidal Rule,
Simpson’s Rule, TI-84
Google of mathematics. Shows steps. Free.
www.wolframalpha.com
7
Numerical Methods
𝑛
𝑏
𝑃0 (π‘₯) = ∫ 𝑓(π‘₯) 𝑑π‘₯ = lim ∑ 𝑓(π‘₯𝑖∗ ) βˆ†π‘₯𝑖
‖𝑃‖→0
π‘Ž
Riemann Sum
𝑖=1
where π‘Ž = π‘₯0 < π‘₯1 < π‘₯2 < β‹― < π‘₯𝑛 = 𝑏
and βˆ†π‘₯𝑖 = π‘₯𝑖 − π‘₯𝑖−1
and ‖𝑃‖ = π‘šπ‘Žπ‘₯{βˆ†π‘₯𝑖 }
Types:
ο‚· Left Sum (LHS)
ο‚· Middle Sum (MHS)
ο‚· Right Sum (RHS)
𝑛
𝑏
𝑃0 (π‘₯) = ∫ 𝑓(π‘₯) 𝑑π‘₯ ≈ ∑ 𝑓(π‘₯̅𝑖 ) βˆ†π‘₯ =
π‘Ž
Midpoint Rule
𝑖=1
βˆ†π‘₯[𝑓(π‘₯Μ…1 ) + 𝑓(π‘₯Μ…2 ) + 𝑓(π‘₯Μ…3 ) + β‹― + 𝑓(π‘₯̅𝑛 )]
𝑏−π‘Ž
where βˆ†π‘₯ =
𝑛
1
and π‘₯̅𝑖 = 2 (π‘₯𝑖−1 + π‘₯𝑖 ) = π‘šπ‘–π‘‘π‘π‘œπ‘–π‘›π‘‘ π‘œπ‘“ [π‘₯𝑖−1 , π‘₯𝑖 ]
Error Bounds: |𝐸𝑀 | ≤
𝑏
𝐾(𝑏−π‘Ž)3
24𝑛2
𝑃1 (π‘₯) = ∫ 𝑓(π‘₯) 𝑑π‘₯ ≈
π‘Ž
Trapezoidal Rule
βˆ†π‘₯
[𝑓(π‘₯0 ) + 2𝑓(π‘₯1 ) + 2𝑓(π‘₯3 ) + β‹― + 2𝑓(π‘₯𝑛−1 )
2
+ 𝑓(π‘₯𝑛 )]
𝑏−π‘Ž
where βˆ†π‘₯ =
𝑛
and π‘₯𝑖 = π‘Ž + π‘–βˆ†π‘₯
Error Bounds: |𝐸𝑇 | ≤
𝑏
𝐾(𝑏−π‘Ž)3
12𝑛2
𝑃2 (π‘₯) = ∫ 𝑓(π‘₯)𝑑π‘₯ ≈
π‘Ž
Simpson’s Rule
βˆ†π‘₯
[𝑓(π‘₯0 ) + 4𝑓(π‘₯1 ) + 2𝑓(π‘₯2 ) + 4𝑓(π‘₯3 ) + β‹―
3
+ 2𝑓(π‘₯𝑛−2 ) + 4𝑓(π‘₯𝑛−1 ) + 𝑓(π‘₯𝑛 )]
Where n is even
𝑏−π‘Ž
and βˆ†π‘₯ = 𝑛
and π‘₯𝑖 = π‘Ž + π‘–βˆ†π‘₯
Error Bounds: |𝐸𝑆 | ≤
𝐾(𝑏−π‘Ž)5
180𝑛4
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Example: [MATH] fnInt(x^2,x,0,1)
1
1
∫ π‘₯ 2 𝑑π‘₯ =
3
0
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8
(http://en.wikipedia.org/wiki/Partial_fraction_deco
mposition)
𝑃(π‘₯)
𝑓(π‘₯) =
𝑄(π‘₯)
where 𝑃(π‘₯) π‘Žπ‘›π‘‘ 𝑄(π‘₯) are polynomials
and degree of 𝑃(π‘₯) < 𝑄(π‘₯)
𝐴
(π‘Žπ‘₯ + 𝑏)
𝐴
𝐡
𝐢
+
+
2
(π‘Žπ‘₯ + 𝑏) (π‘Žπ‘₯ + 𝑏)
(π‘Žπ‘₯ + 𝑏)3
𝐴π‘₯ + 𝐡
2
(π‘Žπ‘₯ + 𝑏π‘₯ + 𝑐)
𝐴π‘₯ + 𝐡
𝐢π‘₯ + 𝐷
𝐸π‘₯ + 𝐹
+
+
(π‘Žπ‘₯ 2 + 𝑏π‘₯ + 𝑐) (π‘Žπ‘₯ 2 + 𝑏π‘₯ + 𝑐)2 (π‘Žπ‘₯ 2 + 𝑏π‘₯ + 𝑐)3
π‘Ž
∫
𝑑π‘₯ = π‘Ž 𝑙𝑛|π‘₯ + 𝑏| + 𝐢
π‘₯+𝑏
π‘Ž
π‘₯
∫ 2
𝑑π‘₯ = π‘Ž π‘‘π‘Žπ‘›−1 ( ) + 𝐢
2
π‘₯ +𝑏
𝑏
Partial Fractions
Condition
Case I: Simple linear (πŸπ’”π’• degree)
Case II: Multiple degree linear (πŸπ’”π’• degree)
Case III: Simple quadratic (πŸπ’π’… degree)
Case IV: Multiple degree quadratic (πŸπ’π’…
degree)
Typical Solution for Cases I & II
Typical Solution for Cases III & IV
Series
Arithmetic
Geometric
lim π‘Žπ‘› = 𝐿 (Limit)
Sequence
𝑛→∞
𝑛
Example: (π‘Žπ‘› , π‘Žπ‘›+1 , π‘Žπ‘›+2 , …)
𝑆𝑛 = ∑ π‘Žπ‘˜
Summation Notation
π‘˜=1
Summation Expanded
Sum of n Terms (finite series)
𝑆𝑛 = π‘Ž1 + π‘Ž2 + β‹― + π‘Žπ‘›−1 + π‘Žπ‘›
(Partial Sum)
𝑛−1
𝑛
π‘˜
𝑆𝑛 = ∑ π‘Ž0 π‘Ÿ = ∑ π‘Ž0 π‘Ÿ π‘˜−1
π‘˜=0
𝑆𝑛 = π‘Ž0 + π‘Ž0 π‘Ÿ + π‘Ž0 π‘Ÿ 2 + β‹― + π‘Ž0 π‘Ÿ 𝑛−1
π‘Ž1 + π‘Žπ‘›
𝑆𝑛 = 𝑛 (
)
2
𝑆𝑛 =
𝑛
(2π‘Ž1 + (𝑛 − 1)𝑑)
2
π‘˜=1
𝑆𝑛 = π‘Ž0
(1 − π‘Ÿ 𝑛 )
1−π‘Ÿ
π‘Ž(1 − π‘Ÿ 𝑛 )
π‘Ž
=
𝑛→∞
1−π‘Ÿ
1−π‘Ÿ
𝑆 = lim
Sum of ∞ Terms (infinite
series)
Recursive nth Term
Explicit nth Term
𝑆→∞
π‘Žπ‘› = π‘Žπ‘›−1 + 𝑑
π‘Žπ‘› = π‘Ž1 + 𝑑(𝑛 − 1)
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
only if |π‘Ÿ| < 1
where π‘Ÿ is the radius of convergence
and (−π‘Ÿ, π‘Ÿ) is the interval of
convergence
π‘Žπ‘› = π‘Žπ‘›−1 π‘Ÿ
π‘Žπ‘› = π‘Ž0 π‘Ÿ 𝑛−1
9
Convergence Tests
(See Harold’s Series Convergence Tests Cheat Sheet)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Convergence Tests
π‘›π‘‘β„Ž Term
Geometric Series
p-Series
Alternating Series
Integral
Ratio
Root
Direct Comparison
Limit Comparison
Telescoping
∞
∑(𝑏𝑛 − 𝑏𝑛+1 )
𝑛=1
Telescoping Series
Converges if lim 𝑏𝑛 = 𝐿
𝑛→ ∞
Diverges if N/A
Sum: 𝑆 = 𝑏1 − 𝐿
Taylor Series
+∞
Power Series
∑ π‘Žπ‘› (π‘₯ − 𝑐)𝑛 = π‘Ž0 + π‘Ž1 (π‘₯ − 𝑐) + π‘Ž2 (π‘₯ − 𝑐)2 + β‹―
𝑛=0
+∞
Power Series About Zero
∑ π‘Žπ‘› π‘₯ 𝑛 = π‘Ž0 + π‘Ž1 π‘₯ + π‘Ž2 π‘₯ 2 + β‹―
𝑛=0
+∞
𝑓 (𝑛) (0) 𝑛
𝑓(π‘₯) ≈ 𝑃𝑛 (π‘₯) = ∑
π‘₯
𝑛!
Maclaurin Series
Taylor series about zero
𝑛=0
𝑓(π‘₯) = 𝑃𝑛 (π‘₯) + 𝑅𝑛 (π‘₯)
+∞
=∑
Maclaurin Series with Remainder
𝑛=0
𝑓 (𝑛) (0) 𝑛 𝑓 (𝑛+1) (π‘₯ ∗ ) 𝑛+1
π‘₯ +
π‘₯
𝑛!
(𝑛 + 1)!
where π‘₯ ≤ π‘₯ ∗ ≤ π‘šπ‘Žπ‘₯
and lim 𝑅𝑛 (π‘₯) = 0
π‘₯→+∞
+∞
Taylor Series
𝑓(π‘₯) ≈ 𝑃𝑛 (π‘₯) = ∑
𝑛=0
𝑓 (𝑛) (𝑐)
(π‘₯ − 𝑐)𝑛
𝑛!
𝑓(π‘₯) = 𝑃𝑛 (π‘₯) + 𝑅𝑛 (π‘₯)
+∞
Taylor Series with Remainder
=∑
𝑛=0
𝑓 (𝑛) (𝑐)
𝑓 (𝑛+1) (π‘₯ ∗ )
(π‘₯ − 𝑐)𝑛 +
(π‘₯ − 𝑐)𝑛+1
𝑛!
(𝑛 + 1)!
where π‘₯ ≤ π‘₯ ∗ ≤ 𝑐
and lim 𝑅𝑛 (π‘₯) = 0
π‘₯→+∞
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
10
Common Series
Exponential Functions
∞
π‘₯𝑛
π‘“π‘œπ‘Ÿ π‘Žπ‘™π‘™ π‘₯
𝑛!
π‘₯
𝑒 =∑
𝑛=0
∞
π‘Ž π‘₯ = 𝑒 π‘₯ ln(π‘Ž) = ∑
𝑛=0
Natural Logarithms
(π‘₯ ln(π‘Ž))𝑛
π‘“π‘œπ‘Ÿ π‘Žπ‘™π‘™ π‘₯
𝑛!
∞
ln (1 − π‘₯) = ∑
𝑛=1
∞
∞
1 + π‘₯ ln(π‘Ž) +
π‘₯𝑛
π‘“π‘œπ‘Ÿ |π‘₯| < 1
𝑛
(−1)𝑛 (π‘₯ − 1)𝑛
ln (π‘₯) = ∑
π‘“π‘œπ‘Ÿ |π‘₯| < 1
𝑛
𝑛=1
1+π‘₯+
π‘₯+
(π‘₯ − 1) +
(−1)𝑛−1 𝑛
π‘₯ π‘“π‘œπ‘Ÿ |π‘₯| < 1
𝑛
ln (1 + π‘₯) = ∑
𝑛=1
π‘₯2 π‘₯3 π‘₯4
+ + +β‹―
2! 3! 4!
(π‘₯ ln(π‘Ž))2 (π‘₯ ln(π‘Ž))3
+
+β‹―
2!
3!
π‘₯2 π‘₯3 π‘₯4 π‘₯5
+ + + +β‹―
2
3
4
5
(π‘₯ − 1)2 (π‘₯ − 1)3 (π‘₯ − 1)4
+
+
+β‹―
2
3
4
π‘₯−
π‘₯2 π‘₯3 π‘₯4 π‘₯5
+ − + −β‹―
2
3
4
5
Geometric Series
∞
1
= ∑(−1)𝑛 (π‘₯ − 1)𝑛 π‘“π‘œπ‘Ÿ 0 < π‘₯ < 2
π‘₯
𝑛=0
1 − (π‘₯ − 1) + (π‘₯ − 1)2 − (π‘₯ − 1)3 + (π‘₯ − 1)4 + β‹―
∞
1
= ∑(−1)𝑛 π‘₯ 𝑛 π‘“π‘œπ‘Ÿ |π‘₯| < 1
1+π‘₯
𝑛=0
1 − π‘₯ + π‘₯2 − π‘₯3 + π‘₯4 − β‹―
∞
1
= ∑ π‘₯ 𝑛 π‘“π‘œπ‘Ÿ |π‘₯| < 1
1−π‘₯
1 + π‘₯ + π‘₯2 + π‘₯3 + π‘₯4 + β‹―
1
= ∑ 𝑛π‘₯ 𝑛−1 π‘“π‘œπ‘Ÿ |π‘₯| < 1
(1 − π‘₯)2
1 + 2π‘₯ + 3π‘₯ 2 + 4π‘₯ 3 + 5π‘₯ 4 + β‹―
𝑛=0
∞
𝑛=1
∞
1
(𝑛 − 1)𝑛 𝑛−2
=∑
π‘₯
π‘“π‘œπ‘Ÿ |π‘₯| < 1
3
(1 − π‘₯)
2
1 + 3π‘₯ + 6π‘₯ 2 + 10π‘₯ 3 + 15π‘₯ 4 + β‹―
𝑛=2
Binomial Series
+∞
π‘Ÿ
(1 + π‘₯) = ∑ ( ) π‘₯ 𝑛
𝑛
π‘Ÿ
𝑛=0
π‘“π‘œπ‘Ÿ |π‘₯| < 1 and all complex r where
𝑛
π‘Ÿ
π‘Ÿ−π‘˜+1
( )=∏
𝑛
π‘˜
π‘˜=1
π‘Ÿ(π‘Ÿ − 1)(π‘Ÿ − 2) … (π‘Ÿ − 𝑛 + 1)
=
𝑛!
Trigonometric Functions
∞
sin (π‘₯) = ∑
𝑛=0
(−1)𝑛 2𝑛+1
π‘₯
π‘“π‘œπ‘Ÿ π‘Žπ‘™π‘™ π‘₯
(2𝑛 + 1)!
∞
cos (π‘₯) = ∑
𝑛=0
(−1)𝑛 2𝑛
π‘₯
π‘“π‘œπ‘Ÿ π‘Žπ‘™π‘™ π‘₯
(2𝑛)!
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
1 + π‘Ÿπ‘₯ +
π‘Ÿ(π‘Ÿ − 1) 2 π‘Ÿ(π‘Ÿ − 1)(π‘Ÿ − 2) 3
π‘₯ +
π‘₯ +β‹―
2!
3!
π‘₯−
π‘₯3 π‘₯5 π‘₯7 π‘₯9
+ − + −β‹―
3! 5! 7! 9!
1−
π‘₯2 π‘₯4 π‘₯6 π‘₯8
+ − + −β‹―
2! 4! 6! 8!
11
∞
𝐡2𝑛 (−4)𝑛 (1 − 4𝑛 ) 2𝑛−1
π‘₯
(2𝑛)!
𝑛=1
πœ‹
π‘“π‘œπ‘Ÿ |π‘₯| <
2
Bernoulli Numbers:
1
1
1
1
𝐡0 = 1, 𝐡1 = , 𝐡2 = , 𝐡4 =
, 𝐡6 = ,
2
6
30
42
1
5
691
7
𝐡8 =
, 𝐡10 =
, 𝐡12 =
, 𝐡14 =
30
66
2730
6
∞
(−1)𝑛 𝐸2𝑛 2𝑛
sec (π‘₯) = ∑
π‘₯
(2𝑛)!
𝑛=0
πœ‹
π‘“π‘œπ‘Ÿ |π‘₯| <
2
Euler Numbers:
𝐸0 = 1, 𝐸2 = −1, 𝐸4 = 5, 𝐸6 = −61,
𝐸8 = 1,385, 𝐸10 = −50,521, 𝐸12 = 2,702,765
∞
(2𝑛)!
arcsin (π‘₯) = ∑ 𝑛 2
π‘₯ 2𝑛+1
(2 𝑛!) (2𝑛 + 1)
tan (π‘₯) = ∑
𝑛=0
π‘“π‘œπ‘Ÿ |π‘₯| ≤ 1
πœ‹
arccos (π‘₯) = − arcsin (π‘₯)
2
π‘“π‘œπ‘Ÿ |π‘₯| ≤ 1
∞
(−1)𝑛 2𝑛+1
arctan (π‘₯) = ∑
π‘₯
(2𝑛 + 1)
π‘₯+2
π‘₯3
π‘₯5
π‘₯7
π‘₯9
+ 16 + 272 + 7936 − β‹―
3!
5!
7!
9!
1
2
17 7
2 9
= π‘₯ + π‘₯3 + π‘₯5 +
π‘₯ +
π‘₯ −β‹―
3
15
315
945
1+
π‘₯2
π‘₯4
π‘₯6
π‘₯8
π‘₯ 10
+ 5 + 61 + 1385 + 50,521
+β‹―
2!
4!
6!
8!
10!
π‘₯+
π‘₯3
1 βˆ™ 3π‘₯ 5 1 βˆ™ 3 βˆ™ 5π‘₯ 7
+
+
+β‹―
2βˆ™3 2βˆ™4βˆ™5 2βˆ™4βˆ™6βˆ™7
πœ‹
π‘₯3
1 βˆ™ 3π‘₯ 5 1 βˆ™ 3 βˆ™ 5π‘₯ 7
−π‘₯−
−
−
−β‹―
2
2βˆ™3 2βˆ™4βˆ™5 2βˆ™4βˆ™6βˆ™7
π‘₯3 π‘₯5 π‘₯7 π‘₯9
π‘₯− + − + −β‹―
3
5
7
9
𝑛=0
π‘“π‘œπ‘Ÿ |π‘₯| < 1, π‘₯ ≠ ±π‘–
Hyperbolic Functions
∞
𝑒 π‘₯ − 𝑒 −π‘₯
π‘₯ 2𝑛+1
sinh (π‘₯) =
=∑
π‘“π‘œπ‘Ÿ π‘Žπ‘™π‘™ π‘₯
(2𝑛 + 1)!
2
π‘₯+
π‘₯3 π‘₯5 π‘₯7 π‘₯9
+ + + +β‹―
3! 5! 7! 9!
𝑒 π‘₯ + 𝑒 −π‘₯
π‘₯ 2𝑛
cosh (π‘₯) =
=∑
π‘“π‘œπ‘Ÿ π‘Žπ‘™π‘™ π‘₯
(2𝑛)!
2
1+
π‘₯2 π‘₯4 π‘₯6 π‘₯8
+ + + +β‹―
2! 4! 6! 8!
𝑛=0
∞
∞
𝑛=0
𝐡2𝑛 4𝑛 (4𝑛 − 1) 2𝑛−1
tanh (π‘₯) = ∑
π‘₯
(2𝑛)!
𝑛=1
πœ‹
π‘“π‘œπ‘Ÿ |π‘₯| <
2
∞
(−1)𝑛 (2𝑛)!
arcsinh (π‘₯) = ∑ 𝑛 2
π‘₯ 2𝑛+1
(2 𝑛!) (2𝑛 + 1)
𝑛=0
π‘“π‘œπ‘Ÿ |π‘₯| ≤ 1
∞
πœ‹
2−𝑛
arccosh (π‘₯) = 𝑖 − 𝑖 ∑
π‘₯ 2𝑛+1
2
𝑛! (2𝑛 + 1)
𝑛=0
π‘“π‘œπ‘Ÿ |π‘₯| ≤ 1
∞
arctanh (π‘₯) = ∑
𝑛=0
π‘₯ 2𝑛+1
(2𝑛 + 1)
π‘“π‘œπ‘Ÿ |π‘₯| < 1, π‘₯ ≠ ±1
Copyright © 2015 by Harold Toomey, WyzAnt Tutor
π‘₯3
π‘₯5
π‘₯7
π‘₯9
π‘₯ − 2 + 16 − 272 + 7936 − β‹―
3!
5!
7!
9!
1 3 2 5 17 7
2 9
π‘₯− π‘₯ + π‘₯ −
π‘₯ +
π‘₯ −β‹―
3
15
315
945
π‘₯−
π‘₯3
1 βˆ™ 3π‘₯ 5 1 βˆ™ 3 βˆ™ 5π‘₯ 7
+
−
+β‹―
2βˆ™3 2βˆ™4βˆ™5 2βˆ™4βˆ™6βˆ™7
πœ‹π‘–
𝑖 π‘₯ 3 𝑖 βˆ™ 1 βˆ™ 3π‘₯ 5 𝑖 βˆ™ 1 βˆ™ 3 βˆ™ 5π‘₯ 7
−𝑖π‘₯−
−
−
−β‹―
2
2βˆ™3
2βˆ™4βˆ™5
2βˆ™4βˆ™6βˆ™7
π‘₯+
π‘₯3 π‘₯5 π‘₯7 π‘₯9
+ + + +β‹―
3
5
7
9
12
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