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MU FE Sem 1 Applied Mathematics-I Most Important Questions with Solutions (Winter 2026)

Practice set · 3 hrs 48 min · 114 marks · for MU Engineering and similar exams

2026, Winter 2026 228 minutes 114 marks Save WhatsApp

Sections

Complex Numbers 4 Q
Hyperbolic Functions & Logarithms of Complex Numbers 4 Q
Partial Differentiation 4 Q
Applications of Partial Differentiation and Successive Differentiation 4 Q
Matrices 4 Q
Numerical Solutions of Equations and Expansion of Functions 4 Q

What this set is

This is an original Doubtly set of 24 most important questions for the Mumbai University FE Semester 1 Applied Mathematics-I (BSC101, NEP 2020 scheme, introduced in 2024-25) exam in Winter 2026. It is not an official university paper and does not predict the actual paper. Questions are grouped module by module, four per module, and every question has a full step-by-step solution. Marks (3, 4, 5 or 6) follow the way such questions are marked in recent MU papers.

How the questions were chosen

We went through the last three Applied Mathematics-I papers (December 2024, June 2025 KT and December 2025) and listed the question type behind every sub-question. Types that came in two or three of these papers, or that carry 5 to 6 marks, were picked. For each type we wrote fresh questions in the same style. Per module, at most one question is taken as-is from those papers, and its stem says which paper it came from.

Module and question typeDec 2024June 2025 KTDec 2025
1. Roots of a complex number / solving \(x^n\) equationsYesYesYes
1. Expansion of \(\sin^m\theta\cos^n\theta\) in multiple anglesYesYesYes
2. Separating real and imaginary parts (tan, tanh, sin of \(x+iy\))NoYesYes
2. Logarithm of a complex numberYesYesYes
3. Euler's theorem and its second-order corollaryYesYesYes
3. Composite functions (chain rule), e.g. \(f(y-z,z-x,x-y)\)YesYesYes
4. Maxima and minima of \(f(x,y)\)YesYesYes
4. \(n^{th}\) derivative and Leibniz's theoremYesYesYes
5. Consistency with \(\lambda,\mu\) (the same system each time)YesYesYes
5. Rank by normal form / PAQYesYesYes
5. Unitary / orthogonal / Hermitian matricesYesYesYes
6. Newton–Raphson methodYesYesYes
6. Gauss–Seidel and Gauss–Jacobi iterationsYesYesYes

One pattern stands out: the \(\lambda,\mu\) system \(x+y+z=6,\ x+2y+3z=10,\ x+2y+\lambda z=\mu\) appeared word for word in all three papers, and the Euler's theorem problem with \(\sin^{-1}\frac{x+y}{\sqrt x+\sqrt y}\) came twice. Those are included as-is (Q.20 and Q.12). Expansion of functions (Taylor and Maclaurin series) is in the Module 6 syllabus but was not asked in these three papers, so revise it from your notes as well.

How to use this set

Try each question on paper first, under time: roughly 1.5 to 2 minutes per mark, the pace of the real 60-mark, 2-hour exam. Then compare your working with the solution, line by line. In MU papers the method carries most of the marks, so practise writing the formula you use, the substitution and the final boxed result, as the solutions do. Every numerical answer and identity here was checked with a computer algebra system. If you can do all 24 confidently, you have covered the question types that came most often in the last three papers.

FAQs

Are these the questions that will come in the Winter 2026 exam?

No one can promise that. These are the question types that repeated most across the last three papers, so they are the best use of revision time, but study the full syllabus too.

Why are some questions marked "asked in MU"?

For each module, one question that the university has already set (some more than once) is included as-is so you can see the exact exam wording. All other questions are new ones of the same type.

What is the actual exam pattern?

The recent papers are 60 marks in 2 hours. Q.1 has short 3-mark questions (attempt any five), and Q.2 to Q.6 each have three parts worth 4, 5 and 6 marks, of which you answer any three questions.

Chapters covered

Instructions

Solve on paper with a timer, then check against the solutions.

Complex Numbers

  1. Q.1 Solve the equation \(x^7+x^4+x^3+1=0\).

    5 marks See answer →
  2. Q.2 Prove that \(\cos^4\theta\sin^3\theta=-\frac{1}{64}\left(\sin7\theta+\sin5\theta-3\sin3\theta-3\sin\theta\right)\).

    6 marks See answer →
  3. Q.3 Using De Moivre's theorem, prove that \((1+i)^8+(1-i)^8=32\).

    3 marks See answer →
  4. Q.4 Find all the values of \(\left(\frac12+i\frac{\sqrt3}{2}\right)^{3/4}\) and show that their continued product is 1. (asked in MU Dec 2025; also in June 2025 KT)

    5 marks See answer →

Hyperbolic Functions & Logarithms of Complex Numbers

  1. Q.5 If \(\tanh x=\frac12\), find the values of \(\sinh2x\) and \(\cosh2x\).

    3 marks See answer →
  2. Q.6 Prove that \(i\log\left(\dfrac{x-i}{x+i}\right)=\pi-2\tan^{-1}x\) for \(x>0\) (principal value).

    4 marks See answer →
  3. Q.7 If \(\sin(\alpha+i\beta)=x+iy\), prove that (i) \(\dfrac{x^2}{\cosh^2\beta}+\dfrac{y^2}{\sinh^2\beta}=1\) and (ii) \(\dfrac{x^2}{\sin^2\alpha}-\dfrac{y^2}{\cos^2\alpha}=1\).

    5 marks See answer →
  4. Q.8 If \(\tan(\alpha+i\beta)=e^{i\theta}\), prove that \(\alpha=\frac{n\pi}{2}+\frac{\pi}{4}\) and \(\beta=\frac12\log\left[\tan\left(\frac\pi4+\frac\theta2\right)\right]\). (asked in MU Dec 2025)

    6 marks See answer →

Partial Differentiation

  1. Q.9 If \(u=\log\left(\dfrac{x^2+y^2}{x+y}\right)\), find the value of \(x\dfrac{\partial u}{\partial x}+y\dfrac{\partial u}{\partial y}\).

    3 marks See answer →
  2. Q.10 If \(u=f\left(\dfrac xy,\dfrac yz,\dfrac zx\right)\), prove that \(x\dfrac{\partial u}{\partial x}+y\dfrac{\partial u}{\partial y}+z\dfrac{\partial u}{\partial z}=0\).

    4 marks See answer →
  3. Q.11 If \(u=\tan^{-1}\left(\dfrac{x^3+y^3}{x-y}\right)\), prove that \(x^2\dfrac{\partial^2u}{\partial x^2}+2xy\dfrac{\partial^2u}{\partial x\partial y}+y^2\dfrac{\partial^2u}{\partial y^2}=\sin4u-\sin2u=2\cos3u\sin u\).

    5 marks See answer →
  4. Q.12 If \(u=\sin^{-1}\left(\dfrac{x+y}{\sqrt x+\sqrt y}\right)\), prove that \(x^2\dfrac{\partial^2u}{\partial x^2}+2xy\dfrac{\partial^2u}{\partial x\partial y}+y^2\dfrac{\partial^2u}{\partial y^2}=-\dfrac{\sin u\cos2u}{4\cos^3u}\). (asked in MU Dec 2024 and June 2025 KT)

    6 marks See answer →

Applications of Partial Differentiation and Successive Differentiation

  1. Q.13 Find the \(n^{th}\) derivative of \(y=\dfrac{x+1}{x^2-4}\).

    4 marks See answer →
  2. Q.14 If \(y=\sin\left(m\sin^{-1}x\right)\), prove that \((1-x^2)y_{n+2}-(2n+1)x\,y_{n+1}+(m^2-n^2)\,y_n=0\).

    5 marks See answer →
  3. Q.15 Discuss the maxima and minima of \(f(x,y)=x^3+3xy^2-15x^2-15y^2+72x\).

    6 marks See answer →
  4. Q.16 Show that the minimum value of \(u=xy+a^3\left(\dfrac1x+\dfrac1y\right)\) is \(3a^2\). (asked in MU June 2025 KT)

    5 marks See answer →

Matrices

  1. Q.17 Show that the matrix \(A=\dfrac12\begin{bmatrix}1+i & -1+i\\ 1+i & 1-i\end{bmatrix}\) is unitary and hence find \(A^{-1}\).

    3 marks See answer →
  2. Q.18 Find \(a,b,c\) if \(A=\dfrac13\begin{bmatrix}1 & 2 & a\\ 2 & 1 & b\\ 2 & -2 & c\end{bmatrix}\) is orthogonal, and write \(A^{-1}\).

    4 marks See answer →
  3. Q.19 Find non-singular matrices \(P\) and \(Q\) such that \(PAQ\) is in normal form, and hence find the rank of \(A=\begin{bmatrix}1&1&2\\1&2&3\\0&-1&-1\end{bmatrix}\).

    6 marks See answer →
  4. Q.20 Investigate for what values of \(\lambda\) and \(\mu\) the system \(x+y+z=6,\ x+2y+3z=10,\ x+2y+\lambda z=\mu\) has (i) no solution, (ii) a unique solution, (iii) infinitely many solutions. (asked in MU Dec 2024, June 2025 KT and Dec 2025)

    6 marks See answer →

Numerical Solutions of Equations and Expansion of Functions

  1. Q.21 Using the Newton–Raphson method, obtain an iterative formula for \(\sqrt N\) and hence find \(\sqrt{30}\) correct to four decimal places.

    3 marks See answer →
  2. Q.22 Using the Newton–Raphson method, find the root of the equation \(2x^3-3x+4=0\) lying between \(-2\) and \(-1\), correct to four places of decimals. (asked in MU Dec 2025)

    5 marks See answer →
  3. Q.23 Solve the following system by the Gauss–Seidel method (three iterations): \(10x+2y+z=9,\ 2x+20y-2z=-44,\ -2x+3y+10z=22\).

    6 marks See answer →
  4. Q.24 Find three sets of iterative solutions by the Gauss–Jacobi method: \(8x+y+2z=16,\ x+6y-z=10,\ 2x-y+9z=27\).

    6 marks See answer →