Tribhuvan University

Institute of Science and Technology

TU Exam Year: 2079

Bachelor Level: B.Sc. CSIT

Semester: First

Subject: Mathematics I (MTH117)

Full Marks: 60 | Pass Marks: 24

Time: 3 Hours

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

SECTION A

Attempt all questions.

  1. 1.
    (a) If a function is defined by \( f(x) = \begin{cases} 1 + x, & x \leq -1 \\ x^2, & x > -1 \end{cases} \), evaluate \( f(-3) \), \( f(-1) \), and \( f(0) \) and sketch the graph.

    (b) Prove that \( \lim_{x \to 0} \frac{|x|}{x} \) does not exist.
  2. 2.
    (a) Sketch the curve \( y = x^2 + 1 \) with the guidelines of sketching.

    (b) If \( z = xy^2 + y^3 \), \( x = \sin t \), \( y = \cos t \), find \( \frac{dz}{dt} \) at \( t = 0 \).
  3. 3.
    (a) Estimate the area between the curve \( y = x^2 \) and the lines \( x = 0 \) and \( x = 1 \), using rectangle method, with four sub intervals.

    (b) A particle moves along a line so that its velocity \( v \) at time \( t \) is \( v = t^2 - 2t + 10 \).

    (i) Find the displacement of the particle during the time period \( 1 \leq t \leq 4 \).

    (ii) Find the distance traveled during this time period.
  4. 4.
    (a) Define initial value problem. Solve: \( y'' + y' - 6y = 0 \), \( y(0) = 1 \), \( y'(0) = 0 \).

    (b) Find the Taylor's series expansion for \( \cos x \) at \( x = 0 \).
  5. 5.
    (a) Dry air is moving upward. If the ground temperature is 20° and the temperature at a height of 2 km is 10°C, express the temperature \( T \) in °C as a function of the height \( h \) (in kilometers), assuming that a linear model is appropriate.

    (b) Draw the graph of the function and find the slope. Hence, give the meaning of the slope.

    (c) What is the temperature at a height of 2 km?
  6. 6.
    Find the equation of tangent at \( (1,3) \) to the curve \( y = 2x^2 + 1 \).
  7. 7.
    State Rolle's theorem and verify the theorem for \( f(x) = x^2 - 9 \), \( x \in [-3, 3] \).
  8. 8.
    Starting with \( x_1 = 1 \), find the third approximation \( x_3 \) to the root of the equation \( x^3 - x - 5 = 0 \).
  9. 9.
    Show that the integral \( \int_0^3 \frac{dx}{x-1} \) diverges.
  10. 10.
    Use Trapezoidal rule to approximate the integral \( \int_1^2 \frac{dx}{x} \) with \( n = 5 \).
  11. 11.
    Find the derivative of \( \mathbf{r}(t) = t^2 \mathbf{i} - t e^{-t} \mathbf{j} + \sin 2t \mathbf{k} \) and find the unit tangent vector at \( t = 0 \).
  12. 12.
    What is a sequence? Is the sequence \( a_n = \frac{n}{5+n} \) convergent?