Higher Engineering Mathematics

(Greg DeLong) #1
INTEGRATION USING TRIGONOMETRIC AND HYPERBOLIC SUBSTITUTIONS 407

H

Hence

∫ 3

2


(x^2 −4) dx

=

[
3
2


5 −2(0.9624)

]
−[0]

= 1. 429 , correct to 4 significant figures

Now try the following exercise.


Exercise 162 Further problems on integra-
tion using the coshθsubstitution


  1. Find



1

(t^2 −16)

dt

[
cosh−^1

x
4

+c

]


  1. Find



3

(4x^2 −9)

dx

[
3
2

cosh−^1

2 x
3

+c

]


  1. Find


∫ √
(θ^2 −9) dθ
[
θ
2


(θ^2 −9)−

9
2

cosh−^1

θ
3

+c

]


  1. Find


∫ √
(4θ^2 −25) dθ

[

θ

√(

θ^2 −

25
4

)

25
4

cosh−^1

2 θ
5

+c

]


  1. Evaluate


∫ 2

1

2

(x^2 −1)

dx [2.634]


  1. Evaluate


∫ 3

2


(t^2 −4) dt [1.429]
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