TAYLOR AND MACLAURIN
how to represent certain types of functions as sums of power series
You might wonder why we would ever want to express a known function
as a sum of infinitely many terms.
Integration. (Easy to integrate polynomials)
Finding limit
Finding a sum of a series (not only geometric, telescoping)
dxe
x
2 2
0
1
lim
x
xe
x
x
TAYLOR AND MACLAURIN
Example:x
exf)(
0n
n
n
x
xce
5
5
4
4
3
3
2
210 xcxcxcxcxcc
Maclaurin series ( center is 0 )
Example:xxf cos)( Find Maclaurin series
TAYLOR AND MACLAURIN
Important Maclaurin Series and Their Radii of Convergence
MEMORIZE: these Maclaurin Series
TAYLOR AND MACLAURIN
Maclaurin series ( center is 0 )
Example:xxf
1
tan)(
Find Maclaurin series
TAYLOR AND MACLAURIN
TERM-081
TAYLOR AND MACLAURIN
TERM-091
TAYLOR AND MACLAURIN
TERM-101
: TAYLOR AND MACLAURIN
TERM-082)2cos(cos
2
1
2
12
xx
Sec 11.9 & 11.10: TAYLOR AND MACLAURIN
TERM-102
Sec 11.9 & 11.10: TAYLOR AND MACLAURIN
TERM-091
TAYLOR AND MACLAURIN
Maclaurin series ( center is 0 )
Example:
0!
1
nn
Find the sum of the series
TAYLOR AND MACLAURIN
TERM-102
TAYLOR AND MACLAURIN
TERM-082
TAYLOR AND MACLAURIN
Leibniz’s formula:
Example: Find the sum
0
12
1
12
)1()(tan
n
n
n
n
x
x
753
)(tan
753
1 xxx
xx
0 12
)1(
n
n
n
7
1
5
1
3
1
1
TAYLOR AND MACLAURIN
Important Maclaurin Series and Their Radii of Convergence
MEMORIZE: these Maclaurin Series
TAYLOR AND MACLAURIN
Important Maclaurin Series and Their Radii of Convergence
Example:)1ln()( xxf Find Maclaurin series
TAYLOR AND MACLAURIN
TERM-102
TAYLOR AND MACLAURIN
TERM-111
TAYLOR AND MACLAURIN
TERM-101
TAYLOR AND MACLAURIN
TERM-082
TAYLOR AND MACLAURIN
Important Maclaurin Series and Their Radii of Convergence
MEMORIZE: these Maclaurin Series
TAYLOR AND MACLAURIN
Maclaurin series ( center is 0)
Taylor series ( center is a)
TAYLOR AND MACLAURIN
TERM-091
TAYLOR AND MACLAURIN
TERM-092
TAYLOR AND MACLAURIN
TERM-082
TAYLOR AND MACLAURIN
Taylor series ( center is a)
Taylor polynomial of order n
DEF:
TAYLOR AND MACLAURIN
TERM-102
The Taylor polynomial of order 3 generated by the function f(x)=ln(3+x) at a=1 is:
Taylor polynomial of order n
DEF:
TAYLOR AND MACLAURIN
TERM-101
TAYLOR AND MACLAURIN
TERM-081
TAYLOR AND MACLAURIN
Taylor series ( center is a)
0
)(
)(
!
)(
)(
k
k
k
ax
k
af
xf
Taylor polynomial of order n
n
k
k
k
n ax
k
af
xP
0
)(
)(
!
)(
)(
Remainder
1
)(
)(
!
)(
)(
nk
k
k
n ax
k
af
xR
Taylor Series )()()( xRxPxf
nn
Remainder consist of infinite terms k
n
n ax
n
cf
xR )(
)!1(
)(
)(
)1(
for some c between a and x.
Taylor’s Formula
REMARK:)(not )(
)1()1(
afcf
nn Observe that :
TAYLOR AND MACLAURIN k
n
n ax
n
cf
xR )(
)!1(
)(
)(
)1(
for some c between a and x.
Taylor’s Formulak
n
n x
n
cf
xR
)!1(
)(
)(
)1(
for some c between 0 and x.
Taylor’s Formula
TAYLOR AND MACLAURIN
Taylor series ( center is a)
nth-degree Taylor polynomial of f at a.
DEF:
Remainder
DEF:)()()( xTxfxR
nn
Example:
01
1
)(
n
n
x
x
xf 32
3
0
3
1)( xxxxxT
n
n
654
4
3
)( xxxxxR
n
n