Fourier transforms, Fourier transforms ,16-42 – HP 50g Graphing Calculator User Manual

Page 519

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Page 16-42

The solution is shown below:

Fourier Transforms

Before presenting the concept of Fourier transforms, we’ll discuss the general
definition of an integral transform. In general, an integral transform is a
transformation that relates a function f(t) to a new function F(s) by an integration

of the form

The function

κ(s,t) is known as the

kernel of the transformation.

The use of an integral transform allows us to resolve a function into a given
spectrum of components. To understand the concept of a spectrum, consider
the Fourier series

representing a periodic function with a period T. This Fourier series can be re-

written as

where

for n =1,2, …

=

b

a

dt

t

f

t

s

s

F

.

)

(

)

,

(

)

(

κ

(

)

,

sin

cos

)

(

1

0

=

+

+

=

n

n

n

n

n

x

b

x

a

a

t

f

ω

ω

=

+

+

=

1

0

),

cos(

)

(

n

n

n

n

x

A

a

x

f

φ

ϖ

,

tan

,

1

2

2

⎟⎟⎠

⎜⎜⎝

=

+

=

n

n

n

n

n

n

a

b

b

a

A

φ

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