Assignment 3
SIN 3005 Numerical Methods and Analysis
Institute of Mathematical Sciences
Universiti Malaya
(Orthogonal polynomials)
1. Find the linear least squares polynomial approximation to f ( x ) on the indicated
interval if
a) f ( x ) = x 2 + 3x + 2, [0,1];
b) f ( x ) = x3 , [0, 2];
1
c) f ( x ) = , 1,3 ;
x
d) f ( x ) = e x , [0, 2];
1 1
e) f ( x ) = cos x + sin 2 x, [0,1];
2 3
f) f ( x ) = x ln x, [1,3].
2. Find the least squares polynomial approximation of degree 2 to the functions and
intervals in Exercise 1.
3. Find the least squares polynomial approximation of degree 2 on the interval [−1, 1] for
the functions in Exercise 2.
4. Use the Gram-Schmidt process to construct 0 ( x ) , 1 ( x ) , 2 ( x ) , and 3 ( x ) for the
following intervals.
a) 0,1
b) 0, 2
c) 1,3
5. Repeat Exercise 1 using the results of Exercise 4.
1
Instructions:
1. All tutorial groups must answer all the questions.
2. Numerical softwares can be used to solve the questions.
3. The due date for Assignment 3 is 18/11/2021.
4. Please upload the solutions in Team SIN 3005.
2
ASSIGNMENT 3 SIN3005
GROUP 3
NUR NAJIA BINTI AHMAD ZAIDI 17133722/2
NURHANNANI BINTI BAHARUDIN 17104646/2
ILI SUHAILA BINTI MOHD NASAR 17120731/1
MUHAMMAD NAJMI BIN HAZLAN 17084513/2
FAREEZ ISKANDAR BIN ZAHARI 17127434/2
(. xh *, [,3] n 1
Sid + * d : S*In x de
a S de , S de Shnx
Parr th mtearotbn
Ca ln o) - 1) 7
4a, 2.9428- 0
26
44, + , =6. 9996
Slye te iltoneaus eauohn
4 + Ba, = S.88 76
, I666 S
Sub into 0
2.943 - 4(I.666s)
2
-I.861/
P , C) = 1.6665 - |.86
4. c),3]
Let . ondond o e othogona1 Polgnanals on Lo,bJ, hen
4, ) x - 8, whae
wge 8, a)[4, )]d« 2
wan le 72,
4 ) = (*-8,) ( ) - Ck sas (),
eoch xi Lob]
wee
fssune wlw) = t.
8, d
d , 3-1
PC) = - 2
S, « *-4x t4) d
a-2 d S-4x t4 d
S 4 +4 d
20-
lo +16
3
x(x3) dr
de
2)n-a)
-
, ce) = (z -
-4x +
Sdve us Sustwone
B2
s'(-a)dx
S
=C-aC*-tut) -a-)
, (a) -2
5e) S) ti,3]
, -2
In 3-In = 0.C493
a,
-d
Cn-a) de 4t4 dr
2Cn 3-a ) o.1922
-
2 = -0.29s8
- 2 ( 3) + 4(2)
. a ) = 0.s493 - 0.29s9 ( »-2)
-0.2953+I.1409
S. 5) ) - x lh , Ci3]
, C)= 4 4wg a. d, w)
lh z de Cah ) -1>
s d
2.9438 = |419
2
4,SCa-a)xhx dx
Cx-a d
Sslve ush fhoe :
a,
.P,Cxd= L.419 + Cn-a)
3
- 13614