Tribhuwan University

Institute of Science and Technology

2080

Bachelor Level / First Year / First Semester / Science

B.Sc in Computer Science and Information Technology (MTH117)

(Mathematics I)

Full Marks: 60

Pass Marks: 24

Time: 3 Hours

Candidates are required to give their answers in their own words as for as practicable.

The figures in the margin indicate full marks.

Section A

Long Answers Questions

Attempt any TWO questions.
[2*10=20]
1.
If a=(4,0,3)\vec{a} = (4,0,3) and b=(2,1,5)\vec{b} = (-2,1,5), find a|\vec{a}|, 3b3\vec{b}, a+b\vec{a} + \vec{b} and 2a+5b2\vec{a} + 5\vec{b}. Estimate the value of
limx0x2+93x2\lim_{x \to 0} \frac{\sqrt{x^2 + 9} - 3}{x^2}
[5+5]
2.
As dry air moves upward, it expands and cools. If the ground temperature is 20C20^{\circ}C and the temperature at height of 1 km is 10C10^{\circ}C, express the temperature TT (in C^{\circ}C) as a function of the height hh (in kilometer), assuming that linear model is appropriate. (a) Draw a graph of the function in part (b). What does the slope represent? (c) What is the temperature at a height of 2.5 km? [5+5]
3.
The area of the parabola y=x2y = x^2 from (1,1) to (2,4) is rotated about the y-axis. Find the area of the resulting surface. Find the solution of the equation y2dy=x2dxy^2 dy = x^2 dx that satisfies the initial condition y(0)=2y(0) = 2. [5+5]
Section B

Short Answers Questions

Attempt any Eight questions.
[8*5=40]
4.
Integrate
01x2x3+1dx\int_0^1 x^2 \sqrt{x^3 + 1} dx
[5]
5.
Find the Maclaurin series expansion of f(x)=exf(x) = e^x at x=0x = 0. [5]
6.
Find where the function f(x)=3x44x312x2+5f(x) = 3x^4 - 4x^3 - 12x^2 + 5 is increasing and where it is decreasing. [5]
7.
Find y' if x3+y3=6xyx^3 + y^3 = 6xy. [5]
8.
Sketch the graph and find the domain and range of the function f(x)=2x1f(x) = 2x - 1. [5]
9.
Determine whether the series converges or diverges
n=1n25n2+4\sum_{n=1}^{\infty} \frac{n^2}{5n^2+4}
[5]
10.
If f(x,y)=x3+x2y32y2f(x, y) = x^3 + x^2y^3 - 2y^2, find fx(2,1)f_x(2,1) and fy(2,1)f_y(2,1). [5]
11.
Show that the function f(x)=x2+7xf(x) = x^2 + \sqrt{7-x} is continuous at x=4x = 4. [5]
12.
Show that y=x1xy = x - \frac{1}{x} is a solution of the differential equation xy+y=2xxy' + y = 2x. [5]