Problem 1 [40 Marks]
1-1. Show that the formula for the best line to fit data (k, Yk) at integers k for 1 ::; k ::; n is y = ax+ b,
[n l l where
6
a= n(n 2 _ l) 2
kyk - (n + 1) n Yk and b = n(n L1. l) [ (2n + 1) n Yk - 3 n kyk
[15]
1-2. Esta bl1. sh t he p ad,e ap- prox1.mat1.0n ex
form.
R~2 ' 2 ( x ) =
12
12
+
-
6x
6x
+
+
x2
X2
ana'
express
R
22
'
m.
contm. ue
d
fractl.on
[10]
1-3. Write down the general formula of Sf (x), the Fourier series of a function f that is 27!"periodic,
piece-wise continuous and defined on (-7r, 7r).
[5]
1-4. Find the Fourier sine series for the 27r-periodic function f(x) = x(1r- x) on (0, 1r). [Hint: Assume f
is an odd function]. Use its Fourier representation to find the value of the infinite series
[10=7+3]
1111
1--+-3-3-+-+5··3· 73 93
Problem 2 [31 Marks]
2-1. Define Tn(x), the nth degree Chebyshev polynomial of the first kind for x E [-1, 1] and show that:
(i) Tk+i(x) = 2xTk(x) -Tk_ 1(x), fork~ l, with T0 (x) = 1, T1(x) = x;
[5]
(ii) Tn has n distinct zeros/roots Xk = cos ( (2k l)1r) for 0::; k::; n - 1.
[7]
2-2. Use the formulae in (i) of question 2-1 to find T2 (x), T3 (x) and then economize
[6]
P(x) = 1 + 2x2 + 3x3 , once.
2-3. Given the integral
3
[
}0
s1in+( 2xxj dx
=
0.6717578646 • • •
2-3-1. Using the sequential trapezoidal rule, state the formula of T(J) = R(J, 0) and then compute its
values for J = 0, l, 2 .
[3+10=13]
Problem 3 [29 Marks]
3-1. For an n-point Gaussian quadrature rule, the Legendre polynomials qn(x), for x E [-1, 1], can be
generated by the recursion formula
qn(x) =
(
-2-n
-
n
1\\I xqn-1(x) -
/
(/-n- - 1\\) qn-2(x)
n1
for n = 2, 3, ...
and qo(x) = 1, q1(x) = x.
3-1-1. Compute q2(x), q3 (x) and determine the zeros of q3 (x).
[2+2+3=7]
3-1-2. Using the zeros of q3 (x) as quadrature nodes, state the associated quadrature formula and deter-
mine the corresponding weights by the method of undetermined coefficients. How do you call the rule thus
obtained?
(2+8+2=12]
65-5] 3-2. Consider the following matrix A= 2 6 -2 . Find its largest eigenvalue (in magnitude) and the
[2 5 -1
corresponding eigenvector after three iterations with the initial vector x<0) = (-1, 1, 1f.
[10]
God bless you !!!