Numerical Method (BSc CSIT, CSC207): the questions likely to come
20 analyzed questions from 7 past papers (2074-2081), grouped by syllabus unit — each with its probability, how often it's been asked, and where to study the answer.
What is curve fitting? Explain the least squares method to fit a straight line y = a + bx to a given set of data points.
Curve Fitting
Curve fitting is the process of constructing a smooth curve (a mathematical function) that best represents the trend of a given set of discrete data points . Unlike interpolation, the fitted curve need not pass through every point; it captures the overall relationship and is used for smoothing data, prediction, and approximating an underlying law. The most widely used technique is the method of least squares.
Least Squares Method for a Straight Line
Given data points , we seek constants and so the line fits best. The error (residual) at each point is . The least squares principle minimizes the sum of squared residuals:
For a minimum, set the partial derivatives to zero:
These give the normal equations:
Solving the two simultaneous equations gives:
Procedure
- Tabulate and compute the column sums.
- Substitute into the formulas for and .
- Write the fitted line .
The resulting line is the best-fit line in the least squares sense, minimizing the total squared vertical distance between the data points and the line.
Interpolation and Approximation
What is curve fitting? Explain the least squares method to fit a straight line y = a + bx to a given set of data points.
Explain Newton's divided difference interpolation formula.
Fit a second-degree parabola y = a + bx + cx^2 to a set of data using the least squares principle.
What is interpolation? Derive Newton's forward and backward difference interpolation formulae and explain when each is used.
State and explain Lagrange's interpolation formula with a suitable example.
Sit a probable paper
A full mock exam built from the most likely questions, mirroring the real paper's structure. Every slot is a real past question.
Most Probable Paper
Mirrors the real structure · 60 marks · based on 7 past papers
- 1.[10 marks]
Explain the Gauss elimination method with partial pivoting to solve a system of linear equations. Solve the system 2x + y + z = 10, 3x + 2y + 3z = 18, x + 4y + 9z = 16.
This question has recurred in 4 of 7 years; so far only in internal assessments, not the board; and its topic (Solution of Linear Algebraic Equations) appears in 100% of years.
- 2.[10 marks]
Explain the fourth-order Runge-Kutta method for solving ordinary differential equations. Solve dy/dx = x + y, y(0) = 1 to find y(0.2) taking h = 0.1.
This question has recurred in 4 of 7 years; so far only in internal assessments, not the board; and its topic (Solution of Ordinary Differential Equations) appears in 86% of years.
- 3.[10 marks]
What is curve fitting? Explain the least squares method to fit a straight line y = a + bx to a given set of data points.
This question has recurred in 3 of 7 years; so far only in internal assessments, not the board; and its topic (Interpolation and Approximation) appears in 100% of years.
- 1.[5 marks]
Differentiate between the Gauss elimination and Gauss-Jordan methods.
This question has recurred in 6 of 7 years; so far only in internal assessments, not the board; and its topic (Solution of Linear Algebraic Equations) appears in 100% of years.
- 2.[5 marks]
Explain numerical differentiation using forward and backward difference formulae.
This question has recurred in 6 of 7 years; so far only in internal assessments, not the board; and its topic (Numerical Differentiation and Integration) appears in 100% of years.
- 3.[5 marks]
Explain Euler's method to solve an ordinary differential equation with an example.
This question has recurred in 6 of 7 years; so far only in internal assessments, not the board; and its topic (Solution of Ordinary Differential Equations) appears in 86% of years.
- 4.[5 marks]
Explain Newton's divided difference interpolation formula.
This question has recurred in 5 of 7 years; so far only in internal assessments, not the board; and its topic (Interpolation and Approximation) appears in 100% of years.
- 5.[5 marks]
Fit a second-degree parabola y = a + bx + cx^2 to a set of data using the least squares principle.
This question has recurred in 5 of 7 years; so far only in internal assessments, not the board; and its topic (Interpolation and Approximation) appears in 100% of years.
- 6.[5 marks]
State and explain Lagrange's interpolation formula with a suitable example.
This question has recurred in 5 of 7 years; so far only in internal assessments, not the board; and its topic (Interpolation and Approximation) appears in 100% of years.
- 7.[5 marks]
Explain the power method for finding the largest eigenvalue of a matrix.
This question has recurred in 5 of 7 years; so far only in internal assessments, not the board; and its topic (Solution of Linear Algebraic Equations) appears in 100% of years.
- 8.[5 marks]
Explain the Gauss-Seidel iterative method to solve a system of linear equations.
This question has recurred in 5 of 7 years; so far only in internal assessments, not the board; and its topic (Solution of Linear Algebraic Equations) appears in 100% of years.
- 9.[5 marks]
Define absolute, relative and percentage errors. Explain the sources of errors in numerical computation.
This question has recurred in 5 of 7 years; so far only in internal assessments, not the board; and its topic recurs in 5 of 7 years.
Behind the numbers
The raw evidence the predictions are computed from: marks per unit per year, syllabus weights, trends, and coverage.
Show the heatmap, topic table and coverage analysis
The receipt: marks per unit, per year
Each row is a syllabus unit, each column an exam year, each cell the marks that unit earned that year. Click any cell to see the actual questions behind it.
| # | Syllabus unit | Probability | Appeared | Avg marks | Syllabus weight | Exam vs syllabus | Trend | Questions |
|---|---|---|---|---|---|---|---|---|
| 1 | U2Interpolation and Approximation | Very likely100% | 17.9 | 22%10 lecture hrs | Balancedexam 24% · syllabus 22% | Steady | 5 recurring5 total | |
| 2 | U4Solution of Linear Algebraic Equations | Very likely100% | 17.1 | 20%9 lecture hrs | Balancedexam 23% · syllabus 20% | Steady | 4 recurring4 total | |
| 3 | U1Solution of Nonlinear Equations | Likely71% | 25 | 20%9 lecture hrs | Balancedexam 24% · syllabus 20% | Steady | 5 recurring5 total | |
| 4 | U3Numerical Differentiation and Integration | Very likely100% | 10.7 | 20%9 lecture hrs | Under-examinedexam 14% · syllabus 20% | Steady | 3 recurring3 total | |
| 5 | U5Solution of Ordinary Differential Equations | Very likely86% | 11.7 | 11%5 lecture hrs | Balancedexam 13% · syllabus 11% | Steady | 2 recurring2 total | |
| 6 | U6Numerical Solution of Partial Differential Equations | Occasional14% | 10 | 7%3 lecture hrs | Balancedexam 2% · syllabus 7% | Steady | none repeat1 total |
Study smart, not hard
Drag the slider: studying the top 4 units in priority order covers ~85% of all observed marks.
- ~80% line
Lecture time vs exam marks
Where the exam pays more than the curriculum spends: ● lectures vs ● exam marks, as a share of the whole course. A long teal-leading bar = high-yield unit.