Tribhuwan University

Institute of Science and Technology

2079

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 function is defined by f(x)={1+x,x1x2,x>1f(x) = \begin{cases} 1 + x, & x \leq -1 \\ x^2, & x > -1 \end{cases}, evaluate f(3)f(-3), f(1)f(-1) and f(0)f(0) and sketch the graph. Prove that limx0xx\lim_{x \to 0} \frac{|x|}{x} does not exist. [10+0]
2.
Sketch the curve y=x2+1y = x^2 + 1 with the guidelines of sketching. If z=xy2+y3z = xy^2 + y^3, x=sintx = \sin t, y=costy = \cos t, find dzdt\frac{dz}{dt} at t=0t = 0. [10+0]
3.
Estimate the area between the curve y=x2y = x^2 and the lines x=0x = 0 and x=1x = 1, using rectangle method, with four sub intervals. A particle moves a line so that its velocity vv at time tt is (1) Find the displacement of the particle during the time period 1t41 \leq t \leq 4 (2) Find the distance travelled during this time period. [10+0]
4.
Define initial value problem. Solve: y+4y6y=0y'' + 4y' - 6y = 0, y(0)=1y(0) = 1, y(0)=0y'(0) = 0 Find the Taylor's series expansion for cosx\cos x at x=0x = 0. [10+0]
Section B

Short Answers Questions

Attempt any Eight questions.
[8*5=40]
5.
Dry air is moving upward. If the ground temperature is 2020^\circ and the temperature at a height of 2km is 1010^\circ, express the temperature TT in ^\circC as a function of the height hh(in km), assuming that a linear model is appropriate. (b) Draw the graph of the function and find the slope. Hence, give the meaning of slope. (c) What is the temperature at a height of 2km? [5]
6.
Find the equation of the tangent at (1,3) to the curve y=x2+1y = x^2 + 1. [5]
7.
State Rolle's theorem and verify the theorem for f(x)=x29f(x) = x^2 - 9, x[3,3]x \in [-3,3]. [5]
8.
Starting with x1=1x_1 = 1, find the third approximate x3x_3 to the root of the equation x3x5=0x^3 - x - 5 = 0. [5]
9.
Show the integral coverages 03dxx1\int_0^3 \frac{dx}{x-1}. [5]
10.
Use Trapezoidal rule to approximate the integral 12dxx\int_1^2 \frac{dx}{x}, with n=5. [5]
11.
Find the derivative of r(t)=t2itetj+sin(2t)k\mathbf{r}(t) = t^2\mathbf{i} - te^{-t}\mathbf{j} + \sin(2t)\mathbf{k} and find the unit tangent vector at t=0t = 0. [5]
12.
What is sequence? Is the sequence an=n5+na_n = \frac{n}{\sqrt{5+n}} convergent? [5]
13.
Find the angle between the vectors a=(2,2,1)a = (2, 2, -1) and b=(1,3,2)b = (1, 3, 2). [5]
14.
Find the partial derivative fxxf_{xx} and fyyf_{yy} of f(x,y)=x2+x3y2y2+xyf(x,y) = x^2 + x^3y^2 - y^2 + xy at (1,2). [5]
15.
Solve 0312x2ydxdy\int_0^3 \int_1^2 x^2y \, dx \, dy [5]