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Calculus 2 Lecture(1)

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URDANETA CITY UNIVERSITY
College of Engineering
and Architecture
Owned and Operated by the City Government of Urdaneta
THE INDEFINITE INTEGRAL
We shall begin our study of the inverse of differentiation. We have learned in differential
calculus that differentiation is the process of finding the derivative or differential of a given
function. This time, we reverse the process, that is, we find the function whose derivative or
differential is given. The inverse of differentiation is called antidifferentiation or integration.
OBJECTIVES. At the end, the student should be able to:
1.
Know the concept of the indefinite integral.
2.
Apply the basic integration formulas.
The symbol ∫ is used to denote the process of integration. The integral of 4π‘₯ 3 is π‘₯ 4 + 𝐢 can
be expressed symbolically as
∫ 4π‘₯ 3 𝑑π‘₯ = π‘₯ 4 + 𝐢
The expression ∫ 4π‘₯ 3 𝑑π‘₯ is called an indefinite integral. Generally, the indefinite integral of a
function f(x) is denoted by ∫ 𝑓(π‘₯)𝑑π‘₯ and defined as follows
∫ 𝑓(π‘₯)𝑑π‘₯ = 𝐹(π‘₯) + 𝐢 if 𝑑𝐹(π‘₯) = 𝑓(π‘₯)𝑑π‘₯ … πΈπ‘žπ‘› (1.1)
We call the symbol ∫ the integral sign, f(x) the integrand, C the arbitrary constant of
integration, and F(x) + C the value of the indefinite integral ∫ 𝑓(π‘₯)𝑑π‘₯. The differential
dx indicates that x is the variable of integration.
1.1 The Indefinite Integral
We know that by differentiation, a derivative or differential is obtained from a given
function. Suppose the derivative (or differential) of a function is given, how can a function be
found? For example, what function has for its derivative 4π‘₯ 3 or for its differential 4π‘₯ 3 𝑑π‘₯? We
𝑑
know that (π‘₯ 4 ) = 4π‘₯ 3 or 𝑑(π‘₯ 4 ) = 4π‘₯ 3 𝑑π‘₯. Thus, the answer to the question above is π‘₯ 4 .
𝑑π‘₯
However, that is not the only possible answer. We may also give the following functions as
valid answers:
π‘₯4 − 3
π‘₯ 4 + 15
π‘₯4 + 8
Table below illustrate further the integral concept:
DIFFERENTIAL
INTEGRAL
𝑑(π‘₯ 6 ) = 6π‘₯ 5 𝑑π‘₯
∫ 6π‘₯ 5 𝑑π‘₯ = π‘₯ 6 + 𝐢
𝑑(π‘₯) = 𝑑π‘₯
∫ 𝑑π‘₯ = π‘₯ + 𝐢
𝑑(𝑒 π‘₯ ) = 𝑒 π‘₯ 𝑑π‘₯
∫ 𝑒 π‘₯ 𝑑π‘₯ = 𝑒 π‘₯ + 𝐢
𝑑(ln π‘₯) =
Notice that from the possible answers, the functions differ only by a constant. If we let C be
any constant, then we may write
𝑑π‘₯
π‘₯
𝑑(sin π‘₯) = cos π‘₯ 𝑑π‘₯
∫
𝑑π‘₯
= ln π‘₯ + 𝐢
π‘₯
∫ cos π‘₯ 𝑑π‘₯ = sin π‘₯ + 𝐢
4
π‘₯ +𝐢
as the general answer.
The function π‘₯ 4 + 𝐢 is called the antiderivative or the integral of4π‘₯ 3 . Antidifferentiation or
integration is the process of finding the function whose derivative or differential is given.
The symbol of differentiation 𝑑, and the symbol of integration ∫ are inverse to each
other. What happens if 𝑑 precedes ∫ or when it follows ∫ ? Let us suppose 𝑓(π‘₯) and
𝐹(π‘₯) are functions whose relationship is given by
𝑑𝐹(π‘₯) = 𝑓(π‘₯)𝑑π‘₯ … (1)
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College of Engineering
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Owned and Operated by the City Government of Urdaneta
Integrating both sides of (1) gives
∫ 𝑑𝐹(π‘₯) = ∫ 𝑓(π‘₯)𝑑π‘₯ … (2)
We have discussed in the preceding section that the process of finding the integral
of a function 𝑓(π‘₯) requires our ability to guess another function 𝐹(π‘₯) whose
derivative is 𝑓(π‘₯) or whose differential is 𝑓(π‘₯)𝑑π‘₯. For example, we guess that
From πΈπ‘žπ‘› (1.1) we see that ∫ 𝑓(π‘₯)𝑑π‘₯ = 𝐹(π‘₯) + 𝐢 . Substituting this in (2), we
have
∫ 3π‘₯ 2 𝑑π‘₯ = π‘₯ 3 + 𝐢 because 𝑑(π‘₯ 3 + 𝐢) = 3π‘₯ 2 𝑑π‘₯.
∫ 𝑑𝐹(π‘₯) = 𝐹(π‘₯) + 𝐢 … πΈπ‘žπ‘› (1.2)
ο‚·
Integrating the differential of a function gives that function plus an
arbitrary constant.
To reduce the amount of guesswork, basic integration formulas, are set up to
facilitate integration. The first six formulas are given below. Note that the letters π‘Ž,
𝑛, and 𝐢 are constants and 𝑓(π‘₯) and 𝑔(π‘₯) are differentiable functions of π‘₯.
For example,
∫ 𝑑(π‘₯ 4 ) = π‘₯ 4 + 𝐢
∫ 𝑑(tan π‘₯) = tan π‘₯ + 𝐢
∫ 𝑑(𝑦) = 𝑦 + 𝐢
∫ 𝑑(𝑒 π‘₯ ) = 𝑒 π‘₯ + 𝐢
1) ∫ 0𝑑π‘₯ = 𝐢
2) ∫ 𝑑π‘₯ = π‘₯ + 𝐢
3) ∫ π‘Žπ‘‘π‘₯ = π‘Žπ‘₯ + 𝐢
π‘₯ 𝑛+1
4) ∫ π‘₯ 𝑛 𝑑π‘₯ = 𝑛+1 + 𝐢
Next, we discuss when 𝑑 precedes ∫ , By πΈπ‘žπ‘› (1.1)
∫ 𝑓(π‘₯)𝑑π‘₯ = 𝐹(π‘₯) + 𝐢 if 𝑑𝐹(π‘₯) = 𝑓(π‘₯)𝑑π‘₯
Differentiating both sides of πΈπ‘žπ‘› (1.1), we get
𝑑[∫ 𝑓(π‘₯)𝑑π‘₯] = 𝑑[𝐹(π‘₯) + 𝐢] = 𝑑𝐹(π‘₯) … (3)
5) ∫ π‘Žπ‘“(π‘₯)𝑑π‘₯ = π‘Ž ∫ 𝑓(π‘₯)𝑑π‘₯
Substituting equation (1), 𝑑𝐹(π‘₯) = 𝑓(π‘₯)𝑑π‘₯, in equation (3), we get
𝑑[∫ 𝑓(π‘₯)𝑑π‘₯] = 𝑓(π‘₯)𝑑π‘₯ … πΈπ‘žπ‘› (1.3)
ο‚·
Note: When 𝒅 precedes∫ , they annul each other.
6) ∫ [𝑓(π‘₯) ± 𝑔(π‘₯)]𝑑π‘₯ =
∫ 𝑓(π‘₯)𝑑π‘₯ + ∫ (𝑔(π‘₯)𝑑π‘₯
For example,
𝑑 ∫ 4π‘₯3𝑑π‘₯ = 4π‘₯3𝑑π‘₯
𝑑 ∫ 𝑠𝑖𝑛π‘₯𝑑π‘₯ = 𝑠𝑖𝑛π‘₯𝑑π‘₯
Proof: 𝑑(𝐢) = 0 βˆ™ 𝑑π‘₯ = 0
Proof: 𝑑(π‘₯ + 𝐢) = 𝑑π‘₯ + 0 = 𝑑π‘₯
Proof:
𝑑(π‘Žπ‘₯ + 𝐢) = 𝑑(π‘Žπ‘‘π‘₯) + 𝑑𝐢 = π‘Žπ‘‘π‘₯
for any rational number 𝑛 ≠ −1
Proof:
π‘₯ 𝑛+1
1
(𝑛 + 1)π‘₯ 𝑛+1−1 𝑑π‘₯
𝑑 (
)=
𝑛+1
𝑛+1
= π‘₯ 𝑛 𝑑π‘₯
Proof:
𝑑(π‘Ž ∫ 𝑓(π‘₯)𝑑π‘₯) = π‘Žπ‘‘ ∫ 𝑓(π‘₯)𝑑π‘₯ =
π‘Ž 𝑓(π‘₯)𝑑π‘₯
Proof:
𝑑[∫ 𝑓(π‘₯)𝑑π‘₯ ± ∫ 𝑔(π‘₯)𝑑π‘₯
= 𝑑∫ 𝑓(π‘₯)𝑑π‘₯
± 𝑑 ∫ 𝑔(π‘₯)𝑑π‘₯]
= 𝑓(π‘₯)𝑑π‘₯ ± 𝑔(π‘₯)𝑑π‘₯
EXAMPLE 1:
1.2 Basic Integration Formulas
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𝑋 4+1
a) ∫ 5π‘₯ 4 𝑑π‘₯ = 5 ∫ π‘₯ 4 𝑑π‘₯ = 5 ( 4+1 ) + 𝐢 = 𝑋 5 + 𝐢
Formula (4)
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b) ∫ 4𝑑π‘₯ = 4∫ 𝑑π‘₯ = 4π‘₯ + 𝐢
Let 𝑒 = π‘₯ + 1, then 𝑑𝑒 = 𝑑π‘₯.
Formula (2)
c) ∫ 6(π‘₯ + 1)𝑑π‘₯ = 6 ∫ (π‘₯ + 1)𝑑π‘₯ = 6[∫ π‘₯𝑑π‘₯ + ∫ 𝑑π‘₯]
= 6[
π‘₯2
+ π‘₯] + 𝐢 = 3π‘₯ 2 + 𝐢
2
Formula (6)
∫ (π‘₯ + 1)4 𝑑π‘₯ =
4+1
+ 𝐢 = (π‘₯ + 1)2 + 𝐢 = 1⁄5 (π‘₯ + 1)5 + 𝐢
Formulas (4) & (2)
d) ∫ (3π‘₯ 5 − 4π‘₯)𝑑π‘₯ = ∫ 3π‘₯ 5 𝑑π‘₯ − ∫ 4π‘₯𝑑π‘₯
Formula (6)
EXAMPLE 2.
Evaluate∫ (2 − 3π‘₯)5 𝑑π‘₯.
= 3∫ π‘₯ 5 𝑑π‘₯ − 4 ∫ π‘₯𝑑π‘₯ Formula (5)
π‘₯6
6
(π‘₯ + 1)4+1
π‘₯2
2
= 3 ( ) − 4 ( ) + 𝐢 Formula (4)
= 1⁄2 π‘₯ 6 − 2π‘₯ 2 + 𝐢
Formula (3)-(6) enables us to evaluate the integral of any polynomial. For instance,
see example 2.
SOLUTION:
Let 𝑒 = 2 − 3π‘₯, then 𝑑𝑒 = −3𝑑π‘₯.
Note that the given integral does not have -3 preceding 𝑑π‘₯. But then -3 can be
written preceding dx if we neutralize it by a factor that we write before the integral
sign. Thus, our new integral will appear in the following manner.
6
(2 − 3π‘₯)
∫ (2 − 3π‘₯)5 𝑑π‘₯ = − 1⁄3 ∫ (2 − 3π‘₯)5 (−3𝑑π‘₯) = − 1⁄3
+𝐢 =
6
= − 1⁄18 (2 − 3π‘₯)6 + 𝐢
EXAMPLE 2:
∫ 8π‘₯ 3 + 12π‘₯ 2 − 4π‘₯ + 5)𝑑π‘₯ = 8∫ 8π‘₯ 3 + 12∫ π‘₯ 2 − 4∫ π‘₯ + 5∫ 𝑑π‘₯
= 2π‘₯ 4 + 4π‘₯ 3 − 2π‘₯ 2 + 5π‘₯ + 𝐢
ο‚·
1.3 The Power Formula
To insert the needed constant legitimately, we must compensate for it by
putting its reciprocal as a factor outside the integral.
EXAMPLE 3.
 7. ∫ 𝑒
Proof: 𝑑 [
𝑛
𝑒𝑛+1
𝑑𝑒 =
+ 𝐢,
𝑛+1
where 𝑛 ≠ −1
𝑒𝑛+1
1
(𝑛 + 1)𝑒𝑛+1 𝑑𝑒 = 𝑒𝑛 𝑑𝑒
+ 𝐢] =
𝑛+1
𝑛+1
Note: The differential 𝑑𝑒 in formula 7 is an exact or complete differential of the
base 𝑒. The exponent 𝑛 is a constant different from -1.
EXAMPLE 1.
Evaluate ∫ (π‘₯ + 1) 𝑑π‘₯.
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SOLUTION:
Let 𝑒 = π‘₯ 2 − 2π‘₯ + 3, then 𝑑𝑒 = 2π‘₯𝑑π‘₯ − 2𝑑π‘₯ = 2(π‘₯ − 1)𝑑π‘₯
∫ (π‘₯ 2 − 2π‘₯ + 3)4 (π‘₯ − 1)𝑑π‘₯ = − 1⁄2 ∫ (π‘₯ 2 − 2π‘₯ + 3)4 (2)(π‘₯ − 1)𝑑π‘₯
= 1⁄10 (π‘₯ 2 − 2π‘₯ + 3)5 + 𝐢
EXAMPLE 4.
4
SOLUTION:
Evaluate ∫ (π‘₯ 2 − 2π‘₯ + 3)4 (π‘₯ − 1)𝑑π‘₯
1
1
Evaluate ∫ tan2 3 π‘₯ 𝑠𝑒𝑐π‘₯ 𝑑π‘₯. sec 2 3 π‘₯𝑑π‘₯.
SOLUTION:
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1
1
1
Let 𝑒 = π‘‘π‘Žπ‘› 3 π‘₯, then 𝑑𝑒 = (sec 2 3 π‘₯) (3 𝑑π‘₯) .
1
1
∫ tan π‘₯ sec 2 π‘₯ 𝑑π‘₯
3
3
𝑑𝑒
 8. ∫ 𝑒−1 𝑑𝑒 = ∫ 𝑒 = 𝐼𝑛𝑒 + 𝐢, 𝑒 ≠ 0. u
2
Proof: 𝑑(𝑙𝑛𝑒 + 𝐢) =
31
tan 3 π‘₯
1
1 1
= 3∫ (tan2 π‘₯) ([sec 2 π‘₯] 𝑑π‘₯) = 3
+𝐢
3
3 3
3
1
= tan3 π‘₯ + 𝐢
3
EXAMPLE 5.
ο‚·
𝑑π‘₯
Evaluate ∫ (π‘₯+1)
SOLUTION:
Let 𝑒 = ln π‘₯, then 𝑑𝑒 =
ln π‘₯ 𝑑π‘₯
=
π‘₯
Formula 8 states that the integral of any quotient whose numerator is the
differential of the denominator is the logarithm of the denominator.
EXAMPLE 1.
ln π‘₯
Evaluate ∫ π‘₯ 𝑑π‘₯
∫
(ln π‘₯ ) 2
2
𝑑π‘₯
.
π‘₯
1
2
+ 𝐢 = ln2 π‘₯ + 𝐢
SOLUTION.
Let 𝑒 = π‘₯ + 1, then 𝑑𝑒 = 𝑑π‘₯. Thus the given integral takes the form of
𝑑𝑒
∫ 𝑒.
∫
EXAMPLE 6.
Evaluate ∫ (1 + 4𝑒 −π‘₯ )(𝑒 −π‘₯ )𝑑π‘₯
SOLUTION.
𝑑π‘₯
= ln(π‘₯ + 1) + 𝐢
π‘₯+1
EXAMPLE 2.
π‘₯ 𝑑π‘₯
Let 𝑒 = 1 + 4𝑒 −π‘₯ , then 𝑑𝑒 = −4𝑒 −π‘₯
∫ (1 + 4𝑒
𝑑𝑒
𝑒
−π‘₯ )(𝑒 −π‘₯
1
1 (1 + 4𝑒 −π‘₯ )5
𝑑π‘₯) = − ∫ (1 + 4𝑒 −π‘₯ )4 (−4𝑒 −π‘₯ 𝑑π‘₯) = −
+𝐢
4
4
5
1
= − (1 + 4𝑒 −π‘₯ )5 + 𝐢
20
Evaluate ∫ π‘₯ 2 −3
SOLUTION.
Let 𝑒 = π‘₯ 2 − 3, then 𝑑𝑒 = 2π‘₯𝑑π‘₯.
π‘₯ 𝑑π‘₯
1
2π‘₯ 𝑑π‘₯
1
∫ π‘₯ 2 −3 = 2 ∫ π‘₯ 2 −3 = 2 ln(π‘₯ 2 − 3) + 𝐢
1.4 Extension of Power Formula
𝑒𝑛+1
The power formula ∫ 𝑒𝑛 𝑑𝑒 = 𝑛+1 + 𝐢 is applicable for any rational number 𝑛
except when 𝑛 = −1. This is so because the power formula is undefined when 𝑛 =
−1. We now extend the power formula for the special case 𝑛 = −1.
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EXAMPLE 3.
𝑒 π‘₯ 𝑑π‘₯
Evaluate ∫ 1+𝑒 π‘₯
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SOLUTION.
= ∫(π‘₯ + 1)𝑑π‘₯ + ∫
Let 𝑒 = 1 + 𝑒 π‘₯ , then 𝑑𝑒 = 𝑒 π‘₯ 𝑑π‘₯.
∫
𝑒 π‘₯ 𝑑π‘₯
= ln(1 + 𝑒 π‘₯ ) + 𝐢
1 + 𝑒π‘₯
EXAMPLE 2.
Evaluate ∫
EXAMPLE 4.
(π‘₯ + 1)2
𝑑π‘₯
=
+ ln(π‘₯ + 1) + 𝐢
π‘₯+1
2
π‘₯ 𝑑π‘₯
√1−π‘₯
SOLUTION.
sec2 3π‘₯𝑑π‘₯
Evaluate ∫ 2+tan 3π‘₯
Rewrite π‘₯ as −[(1 − π‘₯) − 1].
SOLUTION.
∫
Let 𝑒 = 2 + tan 3π‘₯, then 𝑑𝑒 = (sec 2 3π‘₯)(3𝑑π‘₯) .
∫
sec 2 3π‘₯ 𝑑π‘₯ 1 sec 2 3π‘₯ 3𝑑π‘₯ 1
= ∫
= ln(2 + tan 3π‘₯) + 𝐢
2 + tan 3π‘₯ 3 2 + tan 3π‘₯
3
π‘₯ 𝑑π‘₯
√1 − π‘₯
= −∫
(1 − π‘₯) − 1
√1 − π‘₯
3
1
1
𝑑π‘₯ = − ∫[(1 − π‘₯)2 − (1 − π‘₯)−2 ]𝑑π‘₯
1
3
1
(1 − π‘₯)2 (1 − π‘₯)2
2
=−
+
+ 𝐢 = − (1 − π‘₯)2 + 2(1 − π‘₯)2 + 𝐢
3
1
3
2
2
1.5 Algebraic Manipulation
In Differential Calculus, we are asked to differentiate functions or algebraic
equations, and this can be done easily by simply applying the differentiation
formulas. However, in integration problems, it is necessary in some cases to perform
first certain algebraic manipulation to the integrand before an integration formula
will apply. Common algebraic manipulation makes use of expansion or performing
division in rational fractions.
EXAMPLE 3.
Evaluate ∫
𝑑π‘₯
1−𝑒 −π‘₯
SOLUTION.
Multiply both numerator and denominator by 𝑒 π‘₯ .
∫
𝑑π‘₯
𝑒 π‘₯ 𝑑π‘₯
𝑒 π‘₯ 𝑑π‘₯
=
∫
=
∫
= ln(𝑒 π‘₯ − 1) + 𝐢
1 − 𝑒 −π‘₯
𝑒 π‘₯ (1 − 𝑒 −π‘₯ )
𝑒π‘₯ − 1
EXAMPLE 1.
EXAMPLE 4.
π‘₯ 2 𝑑π‘₯
Evaluate ∫ π‘₯+1
(π‘₯+4)𝑑π‘₯
Evaluate ∫ (π‘₯+2)2
SOLUTION.
π‘₯2
1
Performing division gives π‘₯+1 = π‘₯ + 1 + π‘₯+1.
∫
π‘₯ 2 𝑑π‘₯
1
= ∫ (π‘₯ + 1 +
) 𝑑π‘₯
π‘₯+1
π‘₯+1
SOLUTION.
π‘₯+4
(π‘₯+2)+2
Rewrite (π‘₯+2)2 = (π‘₯+2)2 =
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1
π‘₯+2
2
+ (π‘₯+2)2
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(π‘₯ + 4)𝑑π‘₯
𝑑π‘₯
2
−2
∫
=
∫
+
∫
2(π‘₯
+
2)
𝑑π‘₯
=
ln(π‘₯
+
2)
−
+𝐢
(π‘₯ + 2)2
π‘₯+2
π‘₯−2
SOLUTION.
1
Let 𝑒 = π‘π‘œπ‘ π‘₯, then 𝑑𝑒 = −𝑠𝑖𝑛π‘₯𝑑π‘₯ or − csc π‘₯ 𝑑π‘₯
∫
1.6 Integration of Exponential Functions
There are two basic formulas for the integration of exponential functions:

π‘Žπ‘’
9. ∫ π‘Ž 𝑑𝑒 =
+ 𝐢, where π‘Ž
ln π‘Ž
𝑒
𝑒
𝑒
> 0
 10. ∫ 𝑒 𝑑𝑒 = 𝑒 + 𝐢
𝑒 cos π‘₯ 𝑑π‘₯
𝑒 cos π‘₯ 𝑑π‘₯
= −∫
= −𝑒 π‘π‘œπ‘ π‘₯ + 𝐢
csc π‘₯
−csc π‘₯
EXAMPLE 4.
2+𝑒 −π‘₯
Evaluate ∫ (
𝑒 −π‘₯
) 𝑑π‘₯
SOLUTION.
Formula 10 is a special case of formula 9, that is when π‘Ž = 𝑒.
Algebraic manipulation:
2+𝑒 −π‘₯
𝑒 −π‘₯
= 2𝑒 π‘₯ + 1
2 + 𝑒 −π‘₯
∫ ( −π‘₯ ) 𝑑π‘₯ = ∫(2𝑒 π‘₯ + 1)𝑑π‘₯ = ∫ 2𝑒 π‘₯ 𝑑π‘₯ + ∫ 𝑑π‘₯ = 2𝑒 π‘₯ + π‘₯ + 𝐢
𝑒
EXAMPLE 1.
Evaluate ∫ 2π‘₯ 𝑑π‘₯.
SOLUTION.
1.7 Integrals of Hyperbolic Functions
Let 𝑒 = π‘₯, then 𝑑𝑒 = 𝑑π‘₯.
∫ 2π‘₯ 𝑑π‘₯ =
2π‘₯
+𝐢
ln 2
EXAMPLE 2.
Evaluate ∫ 𝑒 −3π‘₯ 𝑑π‘₯
SOLUTION.
The six hyperbolic functions are:
𝑒 𝑒 − 𝑒 −𝑒
sinh 𝑒 =
2
𝑒 𝑒 + 𝑒 −𝑒
cosh 𝑒 =
2
𝑒 𝑒 − 𝑒 −𝑒
tanh 𝑒 = 𝑒
𝑒 + 𝑒 −𝑒
csch 𝑒 =
sech 𝑒 =
coth 𝑒 =
2
𝑒 𝑒 − 𝑒 −𝑒
2
𝑒 𝑒 + 𝑒 −𝑒
𝑒
−𝑒
𝑒 +𝑒
𝑒 𝑒 − 𝑒 −𝑒
Let 𝑒 = −3π‘₯, then 𝑑𝑒 = −3𝑑π‘₯.
1
1
∫ 𝑒 −3π‘₯ 𝑑π‘₯ = − ∫ 𝑒 −3π‘₯ (−3𝑑π‘₯) = − 𝑒 −3π‘₯ + 𝐢
3
3
EXAMPLE 3.
𝑒 𝑐0𝑠π‘₯ 𝑑π‘₯
Evaluate ∫ csc π‘₯
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The derivatives of these functions are as follows:
𝑑
𝑑
(sinh 𝑒) = cosh 𝑒 𝑑𝑒
(cosh 𝑒) = sinh 𝑒 𝑑𝑒
𝑑π‘₯
𝑑π‘₯
𝑑
𝑑
(tanh 𝑒) = sech2 𝑒 𝑑𝑒
(coth 𝑒) = −csch2 𝑒 𝑑𝑒
𝑑π‘₯
𝑑π‘₯
𝑑
(csch 𝑒) = −csch 𝑒 π‘π‘œπ‘‘β„Ž 𝑒 𝑑𝑒
𝑑π‘₯
𝑑
(sech 𝑒) = −sech 𝑒 π‘‘π‘Žπ‘›β„Ž 𝑒 𝑑𝑒
𝑑π‘₯
(075) 600 - 1507 | ucu.edu.ph
San Vicente West, Urdaneta City, Pangasinan
AdrianTomeldan@ucu.edu.ph | +63 917 9579 500
URDANETA CITY UNIVERSITY
College of Engineering
and Architecture
Owned and Operated by the City Government of Urdaneta
Integrating these derivatives, we get the integration formulas for the hyperbolic
functions.
 11. ∫ π‘π‘œπ‘ β„Ž 𝑒 𝑑𝑒 = π‘ π‘–π‘›β„Ž 𝑒 + 𝐢
 12. ∫ π‘ π‘–π‘›β„Žπ‘’ 𝑑𝑒 = π‘π‘œπ‘ β„Ž 𝑒 + 𝐢
 13. ∫ sech2 𝑒 𝑑𝑒 = π‘‘π‘Žπ‘›β„Ž 𝑒 + 𝐢
 14. ∫ csch2 𝑒 𝑑𝑒 = −π‘π‘œπ‘‘β„Ž 𝑒 + 𝐢
 15. ∫ csch 𝑒 π‘π‘œπ‘‘β„Ž 𝑒 𝑑𝑒 = −π‘π‘ π‘β„Ž 𝑒 + 𝐢
 16. ∫ sech 𝑒 π‘‘π‘Žπ‘›β„Ž 𝑒 𝑑𝑒 = −π‘ π‘’π‘β„Ž 𝑒 + 𝐢
EXAMPLES:
1
1
1) ∫ sinh 2π‘₯ 𝑑π‘₯ = 2 ∫(sinh 2π‘₯)2𝑑π‘₯ = 2 cosh 2π‘₯ + 𝐢
π‘₯
π‘₯ 1
π‘₯
2) ∫ cosh 𝑑π‘₯ = 3 ∫(cosh ) 𝑑π‘₯ = 3 sinh + 𝐢
2
3 3
3
𝑒 π‘₯ −𝑒 −π‘₯
3) ∫ tanh π‘₯ 𝑑π‘₯ = ∫ (𝑒 π‘₯ +𝑒 −π‘₯ ) 𝑑π‘₯ = ln(𝑒 π‘₯ + 𝑒 −π‘₯ ) + 𝐢
1
1
4) ∫ sech 3π‘₯ tanh 3π‘₯ 𝑑π‘₯ = ∫ sech 3π‘₯ tanh 3π‘₯ 3𝑑π‘₯ = − sech 3π‘₯ + 𝐢
3
3
𝑑π‘₯
5) ∫ csch2 (ln π‘₯) = − coth(ln π‘₯) + 𝐢
π‘₯
𝑑π‘₯
𝑑π‘₯
6) ∫ sech2 √π‘₯ = 2 ∫ sech2 √π‘₯ ( ) = 2 tanh √π‘₯ + 𝐢
2√π‘₯
√π‘₯
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(075) 600 - 1507 | ucu.edu.ph
San Vicente West, Urdaneta City, Pangasinan
AdrianTomeldan@ucu.edu.ph | +63 917 9579 500
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