Problem 1 [19 Marks]
1-1. Find the Pade approximation R2,2 (x) for f(x) = ln(l +x)/x starting with the MacLaurin expansion
f(x) = 1 - -x + -x2 - -x3 + -x4 - .. · .
23 4 5
[12]
1-2. Use the result in 1-1. to establish ln(l + x)
fraction form.
= R
3
,,
·-
30x
30
++3261xx+2 +9xx-,3,
and
express
R 3'2
in
continued
[7]
Problem 2 [30 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, 1].
2-1. Show the following property:
[5]
Tn has n d1.stm. ct zeros Xk E [-1, 1] : Xk = cos ((_2;k__+-1--)-1'-r-) for 0 :5.k :5.n - 1.
2n
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 + 2x - + x3 3x4 •
(i) Economise the power series f(x).
[3]
(ii) Find the Chebyshev series for f(x).
[5]
;;:; =(;{S)~_;:_xwx'.h•~::e~o~I';:! f:,ction f is even and use an apprnpdate result to find its Fourier se;::;
2 , for 0 :5.X < 7r.
(ii) Set x = 0 and conclude that
1r 2
8
=
1+
1
32
+
1
52
+
1
72
+
···.
[2]
Problem 3 [27 Marks]
3-1. Given the integral
3
{
}0
s1in+( 2xx5) dx
= 0.6717578646 · · ·
3-1-1. Compute T(J) = R(J, 0) for J = 0, 1, 2, 3 using the sequential trapezoidal rule.
[10]
3-1-2. Use the results in 3-1-1. and Romberg's rule to compute the values for the sequential Simpson rule
{ R( J, 1)}, sequential Boole rule {R( J, 2)} and the third impprovement {R( J, 3)}. Display your results in
a tabular form.
[12]
3-2. State the three-point Gaussian Rule for a continuous function f on the interval [-1, 1] and show that
the rule is exact for f (x) = 5x4 .
[5]
1