BT-401 (GS) – Mathematics-III

B.Tech., IV Semester
Examination, November 2022
Grading System (GS)
Max Marks: 70 | Time: 3 Hours

Note:
i) Attempt any five questions.
ii) All questions carry equal marks.

Previous Year Questions (November 2022)

Q.1

a) Use Newton's formula for interpolation to find the net premium at the age 25 from the table given below:

Age20242832
Net Premium0.014270.015810.017720.01996

(Unit 1)


b) Using Newton-Raphson's method find the real root of $x^4 - x - 10 = 0$. (Unit 1)


Q.2

a) Solve the simultaneous linear equations using Crout's method.
$x_1 + x_2 + x_3 = 1$
$3x_1 + x_2 - 3x_3 = 5$
$x_1 - 2x_2 - 5x_3 = 10$ (Unit 2)


b) Evaluate $\int_0^1 \log x \cos x \, dx$ by (i) Trapezoidal rule (ii) Simpson 3/8 rule. (Unit 2)


Q.3

a) Find $y(0.1)$ for differential equation $\frac{dy}{dx} = x^2 y - 1, y(0) = 1$ using Taylor's series method. (Unit 3)


b) Solve $xy'' + y' + xy = 0$, where $y(0) = 1, y'(0) = 0$, for $x = 0$ to $x = 1.5$. (Unit 3)


Q.4

a) Find Laplace transform of $$f(t) = \begin{cases} \sin t & 0 < t < 2\pi \\ 0 & 2\pi < t \end{cases}$$ (Unit 4)


b) Find the Fourier series for periodic extension of $$f(t) = \begin{cases} \sin t, & 0 \le t \le \pi \\ 0, & \pi \le t \le 2\pi \end{cases}$$ (Unit 4)


Q.5

a) If 'm' balls are distributed among 'a' men and 'b' women show that the probability that the number of balls received by men is odd, shall be
$$ \frac{1}{2} \left[ \frac{(b+a)^m - (b-a)^m}{(b+a)^m} \right] $$ (Unit 5)


b) Two independent random variable X and Y are both normally distributed with means 1 and 2 and standard deviations 3 and 4 respectively. If Z = X - Y, write the probability density function of Z. Also state the median, s.d. and mean of the distribution of Z. Find P[Z + 1 $\le$ 0]. (Unit 5)


Q.6

a) Prove that
$$ \Delta^n 0^{n+1} = \frac{n(n+1)}{2} \Delta^n 0^n $$ (Unit 1)


b) Given that $\log x$ for $x = 310, 320, 330, 340, 350$ and $360$ are according to following table. Find the value of $\log 3375$.

$x$310320330340350360
$\log x$2.49136172.50515002.51851392.53147892.54406802.5563025

(Unit 1)


Q.7

a) Use Runge-Kutta method to approximate $y$, when $x = 0.1$ and $x = 0.2$, given that $x = 0$ when $y = 1$ and $\frac{dy}{dx} = x + y$. (Unit 3)


b) Use Milne's method to solve $\frac{dy}{dx} = x + y$ with initial condition $y(0) = 1$, from $x = 0.20$ to $x = 0.30$. (Unit 3)


Q.8

a) Prove that for normal distribution, the Quartile Deviation (QD), Mean Deviation (MD) and Standard Deviation (SD) follows QD : MD : SD :: 10 : 12 : 15. (Unit 5)


b) Prove that
$$ \Delta^n \sin(ax + b) = \left( 2 \sin \frac{ah}{2} \right)^n \sin \left[ ax + b + n \left( \frac{ah + \pi}{2} \right) \right] $$ (Unit 1)