.-
Problem 1 [25 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,
where
l a= n(n26- 1) [2 n kyk - (n + 1) n Yk
l b = n(n 4- 1) [(2n + 1) n Yk - 3 n kyk
[15]
x x: 1-2. Establish the Pade approximation ex R?-,2 (x) = 1122-+6x5+x-+ and express R?-,?- in continued fraction
form.
[10]
Problem 2 [20 Marks]
For any non negative interger n we define Chebyshev polynomial of the first kind as
Tn(x) = cos(n0), where 0 = arccos(x), for x E [-1, l].
2-1. Show that the Chebyshev polynomial Tn is a solution of the differential equation:
[8]
(1 -
x
2
)-
d2 f
dx 2
-
df
x-dx
+n2J =
0.
n.2-2. Compute the expressions of the first five Chebyshev polynomials of the first kind T0 , T1, T2 , T3 and
2-3. Given the trucated power series f(x) = 1 - x - x3 .
(i) Economise the power series J(x).
[3]
(ii) Find the Chebyshev series for f (x).
[5]
Problem 3 [13 Marks]
3-1. Given the integral
13 sin(2x)
o -1--+-,,-x-5dx = 0.6717578646 · · ·
3-1-1. Compute T(J) = R(J, 0) for J = 0, 1, 2, 3 using the sequential trapezoidal rule.
[10]
3-2. State the three-point Gaussian Rule for a continuous function f on the interval [-1, l].
[3]
Problem 4 [32 Marks]
4-1. Assume a 3 x 3 matrix A is known to have three different real eigenvalues >1., >2. and >3.. Assume we
know that >1. is near -2, >2. is near -5 and >.3is near -1.
4-1-1. Explain how the power method can be used to find the values of >1., )..2 and ).3. respectively. [2x3=6]
4-1-2. Discuss how shifting can be used in 4-1-1. to accelerate the convergence of the power method. [2]
1