Problem 1 [29 marks]
1-1. Consider the equation J(x) = ex - x2 + 16 sin(x) - 5 = 0.
1-1-1. Show that f(x) = 0 has a unique solution a in [O1, ].
[6]
1-1-2. Use the Bisection method with initial interval [O,1] to find the approximate solution to
a at the third iteration.
[8]
1-2. Write down Newton's algorithm to approximate the root of a continuous function h in
[a,b]after n iterations.
[3]
1-3. Suppose that g : [a,b]-+ [a,b] is continuous on the real interval [a,b] and is a contraction
in the sense that there exists a constant >.E (0, 1) such that
lg(x) - g(y)J ::::>; -Ix- YI,for all x, y E [a,b].
Prove that there exists a unique fixed point in [a,b] and that the fixed point iteration Xn+1 =
g(xn) converges to it for any x0 E [a,b]. Also, prove that the error is reduced by a factor of at
least >.from each iteration to the next.
[12]
Problem 2. [39 marks]
2-1. Write down in details the formulae of the Lagrange and Newton's form of the polynomial
that interpolates the set of data points (xo, f(xo)), (xi, f(x1)), ... , (xn, f(xn)).
[7]
2-2. Use the results in 2-1. to determine the Lagrange and Newton's form of the polynomial
that interpolates the set of data points (1, 1), (2, 5) and (3, 15).
[18]
2-3. Determine the error term for the formula
[14]
J 111(x)
1
2h 3
[3f(x
+ h)
-
lOJ(x) + l2f(x
-
h) -
6f(x
-
2h) + J(x -
3h)]
Problem 3. [32 marks]
3-1. State the Improved-Euler's algorithm and indicate its order of accuracy.
[4]
3-2. Write down the fourth-order Runge-Kutta (RK4) method's algorithm for the following
specific problem after n steps
[8]
y' (t) = y - t2+ 1, y (0) = 2
3-3. In the kingdom of Bana, king Happi The First asked one of his subjects, a prominent
mathematician to solve the above IVP using the fourth-order Runge-Kutta (RK4) method. He
displayed the results in the form of the following table and purposely skipped some entries.
k tk
k1
k2
k3
k4
Yk
1 0.08 3.0 3.11840
3.24345 2.24969
2 0.16
3.36502
3.49368
3
3.49351 3.61885
2.80885
4
3.75125
3.88567 4.01730
5 0.4
4.15061
4.29200
1