Code No.
6009
FACULTY OF ENGINEERING
B.E. 2/4 (CE/EE/Int/ECE/M/P/AE/CSE) I – Semester (Main.) Examination, December 2013
Subject: Mathematics – III
Time: 3 Hours Max.Marks : 75
Note: Answer all questions from Part – A. Answer any five questions from Part – B.
PART – A (25 Marks)
1. Form a partial differential equation by eliminating the arbitrary function f from
z = eax+by f(ax-by). 3
2. Reduce the partial differential equation z2(p2+q2) = x2+y2 to the form
f(x,p) = g(y,q). 2
3. Find ao in the Fourier series expansion of f(x) = e-x in (-1,1). 2
4. If x = b
n 1
n sin nx, 0 < x < , then find bn. 3
5. Solve py3+qx2 = 0 by the method of separation of variables. 2
6. Solve
u
x
4
u
y ar
, u(0,y) = 8e-3y.
7. Find the iterative formula to find N using Newton-Raphson method.
8. If f(1) = -3, f(3) = 9, f(4) = 30 and f(6) = 132, then find f(x).
9. Find the Z transform of {n an}.
3
2
3
3
el
10. Find the convolution {2n ∗ 3n}. 2
PART – B (50 Marks)
11.(a) Solve y2p – xyq = x (z-2y). 5
t
(b) Solve q(q2+s) = pt by Monge’s method. 5
Es
, x 0
12. Find the Fourier series expansion for f(x) = and hence
x , 0 x
1 1 1
find the sum 2 2 2 ... 10
1 3 5
2 2
u u
13. Solve =0, 0 < x, y < subject to u(0,y) = u( ,y) = u(x, ) = 0
x 2 y 2
and u(x,0) = sin2 x. 10
14.(a) Solve the system of equations 4x – 3y – 9z + 6w = 0, 2x + 3y + 3z+6w= 6
and 4x – 21y – 39z – 6w = -24 by Gauss elimination method. 5
dy
(b) Find the approximate value of y(1.3) for = -2xy2, y(1) = 1 using Euler’s
dx
method. 5
2
7z 11z
15.(a) Find the inverse Z transform of . 5
(z 1)(z 2)(z 3)
(b) State and prove convolution theorem of Z transforms. 5
16. Solve pxy + pq + qy = yz by Charpit’s method. 10
17.(a) Find the Fourier series expansion of f(x) = | cos x| in [- , ]. 5
dy
(b) Find at x = 0.5 from the following table. 5
dx
x: 0 1 2 3
y: 1 3 15 40
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