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9. calculus option

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Topic 9: Calculus Option
Limits of Sequences and Functions
lim [𝑓(π‘₯) + 𝑔(π‘₯)] = lim 𝑓(π‘₯) + lim 𝑔(π‘₯)
$→&
Algebraic
limit laws:
$→&
lim [𝑓(π‘₯) − 𝑔(π‘₯)] = lim 𝑓(π‘₯) − lim 𝑔(π‘₯)
$→&
$→&
$→&
lim [𝑓(π‘₯) × π‘”(π‘₯)] = lim 𝑓(π‘₯) × lim 𝑔(π‘₯)
$→&
$→&
lim 2
$→&
$→&
$→&
lim 𝑓(π‘₯)
𝑓(π‘₯)
3 = $→&
𝑔(π‘₯)
lim 𝑔(π‘₯)
$→&
lim [𝑐𝑓(π‘₯)] = 𝑐 lim 𝑓(π‘₯)
$→&
$→&
L’Hopital’s rule states if the following occurs:
𝒇(𝒙) 𝟎
π₯𝐒𝐦
=
𝒙→𝒂 π’ˆ(𝒙)
𝟎
𝑓(π‘₯) ±∞
lim
=
$→& 𝑔(π‘₯)
±∞
or
Differentiate top and bottom
fraction separately
𝑓(π‘₯) 𝐿′𝐻
𝑓′(π‘₯)
lim
$→& 𝑔(π‘₯) = $→& 𝑔′(π‘₯)
lim
The Squeeze Theorem states if:
Use when involving trigonometric functions
π’ˆ(𝒙) ≤ 𝒇(𝒙) ≤ 𝒉(𝒙)
and
$→&
1
=∞
0>
1
=0
∞
∞
= π‘ˆπ‘›π‘‘π‘’π‘“π‘–π‘›π‘’π‘‘
∞
0
= π‘ˆπ‘›π‘‘π‘’π‘“π‘–π‘›π‘’π‘‘
0
A closed
interval [π‘Ž, 𝑏]
includes end
points
An open
interval (π‘Ž, 𝑏)
excludes end
points
A function is continuous at π‘₯ = π‘Ž when:
lim 𝑓(π‘₯) = lim 𝑓(π‘₯) = limR 𝑓(π‘₯)
lim 𝑓(π‘₯) = 𝐿
Then:
1
= π‘ˆπ‘›π‘‘π‘’π‘“π‘–π‘›π‘’π‘‘
0
Interval
Notation:
lim 𝑔(π‘₯) = lim β„Ž(π‘₯) = 𝐿
$→&
1
= −∞
07
$→&Q
$→&
$→&
$→&
if lim |π‘ŽS | = 0, then lim π‘ŽS = 0
The Absolute Value Theorem states:
S→T
S→T
𝑓(π‘₯) must be continuous at π‘₯V
A function is differentiable at a point π’™πŸŽ if:
𝑓(π‘₯) must not have a “sharp point” at π‘₯V
the tangent to 𝑓(π‘₯) at π‘₯V must be vertical
The derivative of a function 𝒇(𝒙) at the point π’™πŸŽ can be found if the limit exists by:
If not, then the function is not differentiable at that point
𝒇(π’™πŸŽ + 𝒉) − 𝒇(π’™πŸŽ )
𝒉→𝟎
𝒉
𝒇′(π’™πŸŽ ) = π₯𝐒𝐦
or
𝑓(π‘₯) − 𝑓(π‘₯V )
X→V
π‘₯ − π‘₯V
𝑓′(π‘₯V ) = lim
𝑓(π‘₯) is continuous on [π‘Ž, 𝑏]
Rolle’s Theorem requires three
conditions:
a and b are found from the given
interval
𝑓(π‘₯) is differentiable
on (π‘Ž, 𝑏)
𝑓(π‘₯) is continuous on [π‘Ž, 𝑏]
Mean Value Theorem
requires three conditions:
𝑓(π‘₯) is differentiable on ]π‘Ž, 𝑏[
a and b are found from the given
interval
𝑓(π‘Ž)= 𝑓(𝑏)
If three conditions are met then there must be a point 𝒄 such
that 𝒇[ (𝒄) = 𝟎
𝑐 ∈]π‘Ž, 𝑏[
If these conditions are met, then there exists a point 𝑐 such that:
𝑓 [ (𝑐) =
𝑓(𝑏) − 𝑓(π‘Ž)
𝑏−π‘Ž
Topic 9: Calculus Option
Improper Integrals
The Fundamental Theorem of Calculus states if 𝒇(𝒙) is continuous
on [𝒂, 𝒃] where:
𝑭(𝒙) =
𝒙
∫𝒂 𝒇(𝒕) 𝒅𝒕
𝒂≤𝒙≤𝒃
then
The p-series states for:
T
]
𝐹′(π‘₯) = 𝑓(π‘₯)
_
Converges if 𝑝 > 1
1
𝑑π‘₯
π‘₯^
Diverges if 𝑝 ≤ 1
And for any function where π’ˆ(𝒙) such that 𝑭′(𝒙) = 𝒇(𝒙)
g
h
g
g
] 𝑓(π‘₯) 𝑑π‘₯ = ] 𝑓(π‘₯) 𝑑π‘₯ + ] 𝑓(π‘₯) 𝑑π‘₯
𝒃
] 𝒇(𝒙) 𝒅𝒙 = 𝑭(𝒃) − 𝑭(𝒂)
𝒂
&
Where 𝐹(π‘₯) is the
antiderivative of 𝑓(π‘₯)
&
h
&
] = −]
&
g
T
T
Integrals in the form ∫𝒂 𝒇(𝒙) 𝒅𝒙 are known as improper integrals
Convergent when ∫& 𝑓(π‘₯) 𝑑π‘₯ = 0 π‘œπ‘Ÿ 𝑓𝑖𝑛𝑖𝑑𝑒 π‘£π‘Žπ‘™π‘’π‘’
Improper integrals are either convergent or divergent:
T
Divergent when ∫& 𝑓(π‘₯) 𝑑π‘₯ = ±∞
When integrating improper integrals, use π₯𝐒𝐦 and replace ∞ with 𝒕
𝒕→T
T
o
] 𝑓(π‘₯) 𝑑π‘₯ = lim ] 𝑓(π‘₯) 𝑑π‘₯ =
o→T &
&
If 0 ≤ 𝑓(π‘₯) ≤ 𝑔(π‘₯) for all π‘₯ ≥ π‘Ž then:
The Comparison Test for improper
Integrals states:
T
T
∫& 𝑓(π‘₯) 𝑑π‘₯ is convergent if ∫& 𝑔(π‘₯) 𝑑π‘₯ is convergent
T
T
∫& 𝑔(π‘₯) 𝑑π‘₯ is divergent if ∫& 𝑓(π‘₯) 𝑑π‘₯ is divergent
or a decreasing function 𝑓(π‘₯) for all π‘₯ > π‘Ž,
then there is an upper and lower sum such
that:
T
T
T
q 𝑓(π‘˜) < ] 𝑓(π‘₯) 𝑑π‘₯ < q 𝑓(π‘˜)
&
st&>_
st&
The Rienmann Sum states:
For an increasing function 𝑔(π‘₯) for all π‘₯ >
π‘Ž, then there is an upper and lower sum
such that:
T
T
T
q 𝑔(π‘˜) < ] 𝑔(π‘₯) 𝑑π‘₯ < q 𝑔(π‘˜)
st&
&
st&>_
Topic 9: Calculus Option
Series Part 1
T
A series consists of π’‚πŸ + π’‚πŸ + π’‚πŸ‘ …
It is denoted by:
T
q π‘ŽS = 𝑆
q π‘Žs = 𝑆S
St_
st_
For a total sum
For a partial sum
If lim π‘ŽS ≠ 0 or does not exist then ∑ π‘ŽS diverges
S→T
The Divergence Test states:
If lim π‘ŽS = 0 then ∑ π‘ŽS may converge or may diverge
S→T
Geometric Infinite Series:
Converges if |π‘Ÿ| < 1
Diverges if |π‘Ÿ| ≥ 1
T
q π‘Žπ‘Ÿ S7_
Sum of infinite geometric series:
St_
Key series
types:
Telescoping Series:
Partial Fractions
P-Series:
=
Find 𝑆S equation
π‘Ž
1−π‘Ÿ
Take lim 𝑆S
Simplify 𝑆S
_
S→T
Converges if 𝑝 > 1
S}
_
(Harmonic Series: S)
Diverges if 𝑝 ≤ 1
If π‘ŽS ≤ 𝑏S for all of 𝑛 and ∑ 𝑏S converges, then ∑ π‘ŽS also converges
The Comparison Test states given for two
series of positive terms:
If π‘ŽS ≥ 𝑏S for all of 𝑛 and ∑ 𝑏S diverges, then ∑ π‘ŽS also diverges
1. Check if positive (0 ≤ π‘ŽS)
2. Find 𝑏S (𝑏S generally is π‘ŽS take away a useless term)
Steps:
3. Determine whether 𝑏S is smaller or larger than π‘ŽS
3. Find if 𝑏S is convergent or divergent
If ∑
&~
g~
exists and π‘ŽS and 𝑏S are
positive to use limit comparison test:
Then both series either converges of
diverges
The Limit Comparison Test States:
1. Find 𝑏S (𝑏S generally is π‘ŽS take away a useless term)
Steps:
&
2. Find if π‘ŽS and 𝑏S are positive and if ∑ g~ exists
~
T
The Integral Test states for 𝒇(𝒏) = 𝒂𝒏 , if
then
q π‘ŽS
St_
Positive
Decreasing
Continuous
1. Check criteria: If it’s positive decreasing
and continuous
T
]
St_
𝑓(π‘₯)𝑑π‘₯
Will both converge
or diverge
2. Then integrate π‘ŽS
Topic 9: Calculus Option
Series Part 2
The Alternating Series Test states for:
T
if lim |π‘ŽS | = 0 and |π‘ŽS>_ | < |π‘ŽS |, then the series will converge
S→T
q(−𝟏)𝒏 𝒂𝒏
𝒏t𝟏
If: ∑ 𝒂𝒏 converges, then π₯𝐒𝐦 𝑺𝒏 = 𝑺
𝒏→T
However, if 𝒏 does not approach ∞ then
the Error of a Sum can be found:
The Absolute Converge states: For ∑ π‘ŽS, if ∑|π‘ŽS | =
|π‘Ž_ | + |π‘Ž• | + β‹― is convergent, then ∑ π‘ŽS is absolutely
convergent
Use if series is not always
positive, or not
alternating, or when
dealing with trig
1. Write ∑ π‘ŽS as ∑|π‘ŽS |
For alternative series only:
Note:
|𝑹𝒏 | = |𝑺 − 𝑺𝒏 | ≤ 𝒂𝒏>𝟏
Absolute convergence, is stronger than convergence
|πΈπ‘Ÿπ‘Ÿπ‘œπ‘Ÿ| ≤ |𝒂𝒏>𝟏 |
If a series is absolute convergent, it must be convergent
𝒂𝒏>𝟏 ≤ 𝒆𝒓𝒓𝒐𝒓 π’”π’‘π’†π’„π’Šπ’‡π’Šπ’†π’…
Conditional convergence is when series converges, but is not absolutely convergent
&~RŒ
1. lim ‹
S→T
The ratio test stages if:
Don’t need to use divergent test for ratio test
&~
‹ < 1, ∑ π‘ŽS is absolutely convergent
&~RŒ
2. lim ‹
S→T
&~
&~RŒ
3. lim ‹
S→T
&~
‹ > 1, ∑ π‘ŽS is divergent
‹ = 1, ∑ π‘ŽS is inconclusive
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