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Mathematics • Class 12

Linear Programming - Class 12

Master Linear Programming & Optimization through focused practice that strengthens conceptual understanding, problem-solving skills, and the ability to recognize common traps and misconceptions. Explore challenging questions designed to develop deeper reasoning and confident application of key ideas.

Overview

This chapter introduces the concepts and applications of linear programming. It covers graphical methods for solving linear programming problems, such as maximizing or minimizing objective functions subject to linear constraints.

Why This Chapter Matters

  • Linear programming is a critical mathematical technique used in business, economics, and engineering to optimize resource allocation, production, and other processes. This chapter equips you with tools to model and solve optimization problems.

Real-Life Applications

  • Optimizing production and resource allocation in industries and businesses.
  • Solving transportation and logistics problems to minimize costs or maximize efficiency.
  • Designing and managing financial portfolios with optimal returns under constraints.

Skills You Will Learn

  • Understanding the components and formulation of linear programming problems.
  • Solving optimization problems using graphical methods.
  • Applying linear programming techniques to real-world scenarios.

Core Concepts to Master

Boundary Value Theorem

Optimal solutions always occur at vertex points of the feasible region, not necessarily on lines or interiors.

Feasible Region Constancy

Intersection of half-planes defined by constraints; must be non-empty for a solution to exist.

Unbounded Region Trap

If the region is unbounded, an optimal value might not exist; check if the objective function crosses boundaries.

Objective Function Gradient

The slope of the objective function (Ax + By = Z) determines the direction of optimization against constraints.

Multiple Optimal Solutions

Occurs when the objective function line is parallel to a constraint boundary, yielding infinite optimal points.

Non-Negativity Restriction

Constraints x, y ≥ 0 restrict the feasible region to the first quadrant; ignoring this leads to catastrophic errors.

Redundant Constraints

Constraints that do not alter the feasible region; identifying them saves time but requires precise graphical plotting.

Corner Point Method Precision

Evaluation of Z at all vertices is mandatory; intermediate points are irrelevant for linear objective functions.

Inconsistency Detection

Constraints like x + y ≥ 5 and x + y ≤ 2 create an empty feasible region (no solution).

Word Problem Modeling

The art of translating verbal constraints into algebraic inequalities; failure here invalidates all subsequent mathematical work.

Concept Collisions Used by Examiners

Competitive examinations rarely assess concepts in isolation. Instead, examiners intentionally combine multiple concepts from this and related chapters to create higher-order questions that test conceptual reasoning, analytical thinking, and problem-solving ability. The concept collision patterns below represent the combinations most frequently used while designing questions for this chapter.

Boundary Value Theorem
Coefficient of x^r in Expansion
Factor Theorem in Determinants
Boundary Value Theorem
Condition of Collinearity
Reflection Principle
Boundary Value Theorem
Determinant as Geometric Area/Volume
Modulus Inequality Logic
Critical Point vs Stationary Point
Boundary Value Theorem
Exact Differential Recognition
Unbounded Region Trap
Inequalities in Definite Integrals
Boundary Value Theorem
Fundamental Theorem of Calculus
Even and Odd Function Symmetry
Auxiliary Angle Method
Boundary Value Theorem
Global Extrema on Intervals
The Zero-Factor Cancellation Trap
Boundary Value Theorem
Linearity and Partitioning
Compound Function Boundaries
Boundary Value Theorem
LMVT Tangent Parallelism
Triangle Inequality Mind Games
Boundary Value Theorem
Non-Negativity Restriction
Line lying in a plane
Coordinate Axis Projections
Boundary Value Theorem
Variance of Discrete Variable
Calculation of Variance for Grouped Data
Feasible Region Constancy
Adjoint-Determinant Relation
Determinant Scaling Property
Matrix Multiplication Non-Commutativity
Feasible Region Constancy
Area of Triangle via Determinants
The Modulus Trap
Feasible Region Constancy
Coplanarity Condition
Linear Independence vs Dependence
Feasible Region Constancy
Determinant as Geometric Area/Volume
Greatest Integer Function Traps
Feasible Region Constancy
Increasing/Decreasing Strictness
Second Derivative Test Limitations
Feasible Region Constancy
Increasing/Decreasing Strictness
Step Function Discontinuities
Feasible Region Constancy
Line-Plane intersection logic
Direction Cosines constraint
Feasible Region Constancy
Maximum/Minimum of Quadratic Expressions
Cross Multiplication Trap
Unbounded Region Trap
Corner Point Method Precision
Right-Hand vs Left-Hand Derivatives
Unbounded Region Trap
General Conic Definition
Symmetry and Periodicity
Unbounded Region Trap
Linear Independence vs Dependence
Integration Constant Trap
Unbounded Region Trap
Linear Independence vs Dependence
Parametric form pitfalls
Unbounded Region Trap
Multiple Optimal Solutions
Domain Constraint Intersections
Unbounded Region Trap
Multiple Optimal Solutions
The L'Hôpital's Rule Misuse
Compound Function Boundaries
Objective Function Gradient
Characteristic Equation
Row/Column Exchange Parity
Objective Function Gradient
Determinant as Geometric Area/Volume
Row/Column Exchange Parity
Objective Function Gradient
Differentiation of Determinants
Modulus Function Breakdown
Objective Function Gradient
Locus via Distance Constraints
Direction Cosines constraint
Objective Function Gradient
Redundant Constraints
Modulus Sign Dependency
Objective Function Gradient
Tangent/Normal Slope Interplay
Closed vs Open Intervals
Objective Function Gradient
The Telescopic Series Trap
Even Multiplicity Roots
Objective Function Gradient
Unbounded Region Trap
Rational Function Asymptotes
Objective Function Gradient
Vector Triple Product Expansion
Lagrange Identity
Objective Function Gradient
Word Problem Modeling
Sign Flipping Rule
Modulus Sign Dependency
Multiple Optimal Solutions
Condition of Collinearity
Geometry of Complex Inequalities
Multiple Optimal Solutions
De Moivre’s Theorem Applications
Geometry of Complex Inequalities
Multiple Optimal Solutions
Intersection Point Accuracy
Step Function Discontinuities
Multiple Optimal Solutions
Objective Function Gradient
Normal Form Parameters
Multiple Optimal Solutions
Redundant Constraints
Modulus Sign Dependency
Multiple Optimal Solutions
Sigma Notation Properties
Binomial Coefficient Summation Properties
Multiple Optimal Solutions
Slope Sensitivity
Tangent/Normal Slope Interplay
Non-Negativity Restriction
Direction Cosines constraint
Linear Independence vs Dependence
Non-Negativity Restriction
Non-Differentiable Extrema
Modulus Function Breakdown
Non-Negativity Restriction
Probability Mass Function (PMF)
Principal Value Branch Boundaries
Non-Negativity Restriction
Probability Mass Function (PMF)
Random Variable Expectation
Non-Negativity Restriction
Symmetric and Skew-Symmetric Decomposition
Matrix Equality
Non-Negativity Restriction
Triangle Inequality Mind Games
Algebraic Manipulation of i
Redundant Constraints
Condition for Common Roots
Quadratic Roots in Sequences
Redundant Constraints
Geometry Constraint Modeling
Non-Differentiable Extrema
Global Extrema on Intervals
Redundant Constraints
Surjective Mapping (Onto)
Domain Restrictions
Corner Point Method Precision
Condition of Tangency
Family of Lines
Corner Point Method Precision
Geometry Constraint Modeling
Modulus Function Breakdown
Corner Point Method Precision
Geometry Constraint Modeling
Slope Sensitivity
Distance Between Parallel Lines
Corner Point Method Precision
Inequalities in Definite Integrals
The Sign-Consistency Principle
Horizontal vs Vertical Strips
Corner Point Method Precision
Line lying in a plane
Unit Vector Normalization
Collinearity and Coplanarity
Corner Point Method Precision
Multiple Optimal Solutions
Quadratic Roots in Sequences
Corner Point Method Precision
Objective Function Gradient
Wavy Curve (Method of Intervals)
Greatest Integer Function Traps
Corner Point Method Precision
Random Variable Mapping
Variance of Discrete Variable
Equiprobable Outcomes
Inconsistency Detection
Binomial Coefficient Summation Properties
Numerically Greatest Term
Inconsistency Detection
Feasible Region Constancy
Limit Existence at Discontinuity
Inconsistency Detection
Geometry of Complex Inequalities
Domain and Range Nuance
Inconsistency Detection
Integral Part and Fractional Part
Step Function Discontinuities
Inconsistency Detection
Intersection of Conics
Domain Constraint Intersections
Inconsistency Detection
Matrix Trace Properties
Matrix Multiplication Non-Commutativity
Inconsistency Detection
Orthogonal Trajectories
Integrating Factor (IF) Sign Sensitivity
Inconsistency Detection
Singular vs Non-Singular Matrices
Skew-Symmetric Determinant
Word Problem Modeling
Determinant as Geometric Area/Volume
Triangle Inequality Mind Games
Word Problem Modeling
Distance from point to plane
Octant Sign Convention
Word Problem Modeling
Fundamental Principle of Counting (FPC)
Integral Part and Fractional Part
Cardinality Inclusion-Exclusion
Word Problem Modeling
General vs Particular Solutions
Sum to n terms vs. General Term
Infinite Limit Behavior
Word Problem Modeling
Geometry Constraint Modeling
Modulus Function Symmetry
Domain Constraint Intersections
Word Problem Modeling
Increasing/Decreasing Strictness
Mean Value Theorem Applicability
Word Problem Modeling
Multiple Optimal Solutions
Differentiation of Determinants
Nilpotent Matrix Logic
Word Problem Modeling
Redundant Constraints
Slope Sensitivity
Euler's Form and Rotations
Word Problem Modeling
System of Linear Equations (Cramer/Inverse)
Idempotent and Involutory Properties

Exam Coverage

Understand how this chapter is tested across major competitive examinations.

JEE Advanced

India · Competitive Exam · Undergraduate

JEE Main

India · Competitive Exam · Undergraduate

BITSAT

India · Competitive Exam · Undergraduate

IISER Aptitude Test (IAT)

India · Competitive Exam · Undergraduate

NEST

India · Competitive Exam · Undergraduate

ISI Admission Test

India · Competitive Exam · Undergraduate

CMI Entrance

India · Competitive Exam · Undergraduate

IOQM / INMO

India · Olympiad · High School

SAT Math

United States · Curriculum · High School

A-Level Mathematics

United Kingdom · Curriculum · Advanced Level

A-Level Further Mathematics

United Kingdom · Curriculum · Advanced Level

Singapore A-Level Mathematics

Singapore · Curriculum · Advanced Level

Cambridge International A-Level Mathematics

International · Curriculum · Cambridge

International Mathematical Olympiad (IMO)

International · Olympiad · International

Practice Questions

Strengthen your understanding by solving carefully selected questions from this chapter.

50 Questions
1

Let RR be the feasible region in the first quadrant of the xyxy-plane defined by the system of inequalities: x≤5x \le 5 y≤6y \le 6 x2y−8xy+16y≤x3−8x2+16xx^2 y - 8xy + 16y \le x^3 - 8x^2 + 16x Find the maximum value of the objective function Z=4x+5yZ = 4x + 5y over the region RR.

2

Let a line LL lie in the plane P:2x+y+2z=12P: 2x + y + 2z = 12. The projection of the line LL onto the yzyz-plane is the line given by the equation y−2z=4y - 2z = 4. Let SS be the set of all points (x,y,z)(x,y,z) on LL that satisfy the non-negativity conditions x≥0x \ge 0, y≥0y \ge 0, and z≥0z \ge 0. If MM and mm are the absolute maximum and absolute minimum values of the function f(x,y,z)=x2+y2+z2−6z−22f(x,y,z) = x^2 + y^2 + z^2 - 6z - 22 on the set SS, respectively, find the value of M+mM + m.

3

Let SS be the region in the xyxy-plane defined by the inequalities x≥0x \ge 0, y≥0y \ge 0, x+y≤4x + y \le 4, and 2x+y≤62x + y \le 6. Let f(θ)=max⁡(x,y)∈S(xcos⁡θ+ysin⁡θ)f(\theta) = \max_{(x,y) \in S} (x \cos \theta + y \sin \theta) for θ∈[0,π2]\theta \in \left[0, \frac{\pi}{2}\right]. Find the value of the integral ∫0π/2f(θ)dθ\int_0^{\pi/2} f(\theta) d\theta.

4

Let α\alpha and β\beta be the coefficients of x5x^5 and x3x^3 respectively in the binomial expansion of (1−x2)4(1−x)3(1-x^2)^4 (1-x)^3.

Consider the determinants: Δ1(x,y)=∣111xyαx3y3α3∣andΔ2(x,y)=∣111xyβx2y2β2∣\Delta_1(x,y) = \begin{vmatrix} 1 & 1 & 1 \\ x & y & \alpha \\ x^3 & y^3 & \alpha^3 \end{vmatrix} \quad \text{and} \quad \Delta_2(x,y) = \begin{vmatrix} 1 & 1 & 1 \\ x & y & \beta \\ x^2 & y^2 & \beta^2 \end{vmatrix}

Let L1(x,y)=0L_1(x,y) = 0 be the line obtained from the linear factor of Δ1(x,y)\Delta_1(x,y) that has a negative slope. Let L2(x,y)=0L_2(x,y) = 0 and L3(x,y)=0L_3(x,y) = 0 be the lines obtained from the linear factors of Δ2(x,y)\Delta_2(x,y) that have zero and infinite slopes, respectively. Assume the leading coefficients of xx and yy in the expressions for L1,L2,L_1, L_2, and L3L_3 are taken as positive.

Let RR be the feasible region in the first quadrant (x≥0,y≥0x \ge 0, y \ge 0) satisfying the constraints L1(x,y)≤0L_1(x,y) \le 0, L2(x,y)≤0L_2(x,y) \le 0, and L3(x,y)≤0L_3(x,y) \le 0. Find the maximum value of the objective function Z=5x+7yZ = 5x + 7y on the region RR.

5

Let x,y,x, y, and zz be the side lengths of a non-degenerate triangle such that z=1z = 1 and the perimeter of the triangle is 33. Consider the function f(x,y)=x3+y3−3xyf(x, y) = x^3 + y^3 - 3xy. If MM and mm are the supremum and infimum of f(x,y)f(x, y) respectively, then the value of 4(M−m)4(M - m) is:

6

Let RR be the feasible region in the xyxy-plane defined by x≥0,y≥0x \ge 0, y \ge 0 and the determinant constraints: ∣[x][y]12∣≤202,∣[x]−[y]21∣≤202\begin{vmatrix} [x] & [y] \\ 1 & 2 \end{vmatrix} \le 202, \quad \begin{vmatrix} [x] & -[y] \\ 2 & 1 \end{vmatrix} \le 202 where [⋅][ \cdot ] denotes the greatest integer function. If MM is the supremum of the objective function Z=4x+3yZ = 4x + 3y for (x,y)∈R(x,y) \in R, find the value of MM.

7

Let S={(x,y)∈R2:0≤x≤5,0≤y≤5,x−3y−2≥1}S = \left\{ (x, y) \in \mathbb{R}^2 : 0 \le x \le 5, 0 \le y \le 5, \frac{x - 3}{y - 2} \ge 1 \right\}. Find the supremum of the function f(x,y)=x2+y2−10x−10y+50f(x, y) = x^2 + y^2 - 10x - 10y + 50 over the set SS.

8

Let f:[0,3]→Rf: [0, 3] \to \mathbb{R} be defined as f(x)=∫0x(4t+1−6⌊t⌋)dtf(x) = \int_0^x (4t + 1 - 6\lfloor t \rfloor) dt where ⌊t⌋\lfloor t \rfloor denotes the greatest integer less than or equal to tt. Find the absolute maximum value of f(x)f(x) on the interval [0,3][0, 3].

9

Let SS be the set of all vectors v⃗=li^+mj^+nk^\vec{v} = l\hat{i} + m\hat{j} + n\hat{k} where l,m,nl, m, n are the direction cosines of a ray originating from the origin OO. The ray intersects the plane P1:3x+4y+12z=68P_1: 3x + 4y + 12z = 68 at point AA and the plane P2:x+2y+2z=6P_2: x + 2y + 2z = 6 at point BB. If OA=5OA = 5 and OB=3OB = 3, then the number of elements in SS is:

10

Consider the linear programming problem: Maximize Z=(lim⁡x→0tan⁡x−sin⁡xx3)x+(lim⁡x→0ln⁡(cos⁡(2x))x2)yZ = \left( \lim_{x \to 0} \frac{\tan x - \sin x}{x^3} \right) x + \left( \lim_{x \to 0} \frac{\ln(\cos(\sqrt{2}x))}{x^2} \right) y subject to the constraints: x−2y≤lim⁡x→0ex2−cos⁡(2x)x2x - 2y \le \lim_{x \to 0} \frac{e^{x^2} - \cos(\sqrt{2}x)}{x^2} x+y≥lim⁡x→0e3x−1sin⁡xx + y \ge \lim_{x \to 0} \frac{e^{3x} - 1}{\sin x} x≥0,y≥0x \ge 0, y \ge 0 Which of the following statements is true regarding the optimal solution?

11

Let a⃗=ti^+j^+k^\vec{a} = t\hat{i} + \hat{j} + \hat{k}, b⃗=i^+tj^+k^\vec{b} = \hat{i} + t\hat{j} + \hat{k}, and c⃗=i^+j^+tk^\vec{c} = \hat{i} + \hat{j} + t\hat{k} be three linearly dependent vectors, where tt is a real number such that t<0t < 0. Consider the following Linear Programming Problem:

Maximize Z=4x+3yZ = 4x + 3y Subject to the constraints: r⃗⋅(i^+j^)≥1\vec{r} \cdot (\hat{i} + \hat{j}) \ge 1 r⃗⋅(ti^+j^)≤4\vec{r} \cdot (t\hat{i} + \hat{j}) \le 4 x≥0,y≥0x \ge 0, y \ge 0 where r⃗=xi^+yj^\vec{r} = x\hat{i} + y\hat{j}.

The maximum value of ZZ is:

12

Let SS be the feasible region in the xyxy-plane defined by the inequalities: y−∣2x−4∣≥0y - |2x - 4| \ge 0 2x−y+2≥02x - y + 2 \ge 0 Find the maximum value of the objective function Z=5x−2yZ = 5x - 2y on the region SS.

13

A factory produces two liquids, XX and YY. The daily production constraints are x+y≥6x + y \ge 6, x≤6x \le 6, and y≤6y \le 6, where x,y≥0x, y \ge 0 are the quantities in kiloliters. The daily operating cost (in thousands of rupees) is modeled by the objective function C(x,y)=4∣x−y∣+x+yC(x,y) = 4|x - y| + x + y. What is the minimum possible daily operating cost?

14

Let M=(510101015)M = \begin{pmatrix} 5 & 1 & 0 \\ 1 & 0 & 1 \\ 0 & 1 & 5 \end{pmatrix} and J=(001010100)J = \begin{pmatrix} 0 & 0 & 1 \\ 0 & 1 & 0 \\ 1 & 0 & 0 \end{pmatrix}. A function f:R→Rf: \mathbb{R} \to \mathbb{R} is defined as f(x)=det⁡(M+xJ)f(x) = \det(M + xJ). Find the local maximum value of f(x)f(x).

15

Let SS be the set of all points P(x,y,z)P(x,y,z) in R3\mathbb{R}^3 such that the distance of PP from the origin OO is 232\sqrt{3}, and the sum of the direction cosines of the position vector OP⃗\vec{OP} is 11. Let v⃗=3i^+3j^\vec{v} = 3\hat{i} + 3\hat{j}. If MM and mm are the absolute maximum and minimum values of the dot product OP⃗⋅v⃗\vec{OP} \cdot \vec{v} for all P∈SP \in S, then the value of M2+m2M^2 + m^2 is equal to:

16

Let RR be the region in the xyxy-plane consisting of all points (x,y)(x, y) that satisfy the conditions: x2+y2≤36x^2 + y^2 \le 36 ∑k=272x−2k−1(x−k)2(x−k−1)2≥0\sum_{k=2}^{7} \frac{2x - 2k - 1}{(x-k)^2 (x-k-1)^2} \ge 0 Let MM be the supremum of the objective function Z=x+yZ = x + y over the region RR. Find the value of MM.

17

Let f:R→Rf: \mathbb{R} \to \mathbb{R} be defined as f(x)=∣ln⁡(1+x2)∣x2−3∣1∣x2−3∣11111∣f(x) = \begin{vmatrix} \ln(1+x^2) & |x^2-3| & 1 \\ |x^2-3| & 1 & 1 \\ 1 & 1 & 1 \end{vmatrix} Let SS be the set of all points of local extrema (both local maxima and local minima) of the function f(x)f(x). Find the value of ∑x∈Sx2\sum_{x \in S} x^2.

18

Let the feasible region RR in the xyxy-plane be defined by the system of inequalities: x≥0,y≥0x \ge 0, \quad y \ge 0 x−y≤2x - y \le 2 x+3y≤6x + \sqrt{3}y \le 6 Let SS be the set of all values θ∈[0,2π)\theta \in [0, 2\pi) such that the objective function Z=xcos⁡θ+ysin⁡θZ = x \cos \theta + y \sin \theta attains its maximum value on RR at infinitely many points. Find the value of ∑θ∈Sθ\sum_{\theta \in S} \theta.

19

Consider the linear programming problem: Minimize Z=3x+yZ = 3x + y subject to the constraints: y−3∣x−4∣≥3y - 3|x - 4| \ge 3 3x+y≥123x + y \ge 12 x+y≤13x + y \le 13 2x−y≤102x - y \le 10 x≥0,y≥0x \ge 0, y \ge 0 Let SS be the set of all points (x,y)(x,y) in the feasible region at which ZZ attains its minimum value. If SS is a line segment of length LL, find the value of L2L^2.

20

Let SS be the region in the complex plane consisting of all z=x+iyz = x+iy satisfying the following system of inequalities: ∣z−2∣≤∣z+2∣|z - 2| \le |z + 2| ∣z−2i∣≤∣z+2i∣|z - 2i| \le |z + 2i| ∣z∣≥∣z−2−2i∣|z| \ge |z - 2 - 2i| ∣z−4∣≤∣z−8∣|z - 4| \le |z - 8| ∣z−4i∣≤∣z−8i∣|z - 4i| \le |z - 8i| ∣z−3−3i∣≤∣z−5−5i∣|z - 3 - 3i| \le |z - 5 - 5i| Let f(z)=Re((1−i)z)f(z) = \text{Re}((1-i)z). If MM is the maximum value of f(z)f(z) for z∈Sz \in S, and EE is the set of all points z∈Sz \in S such that f(z)=Mf(z) = M, find the length of the line segment representing EE.

21

Consider the linear programming problem: Maximize Z=c1x+c2yZ = c_1 x + c_2 y Subject to the constraints: x≥0,y≥0x \ge 0, y \ge 0 x+λy≤Lx + \lambda y \le L 3x+2y≤153x + 2y \le 15 where c1=2(2412)∑r=012(12r)2c_1 = \frac{2}{\binom{24}{12}} \sum_{r=0}^{12} \binom{12}{r}^2, c2=2(2412)∑r=012r(12r)2c_2 = \frac{2}{\binom{24}{12}} \sum_{r=0}^{12} r \binom{12}{r}^2, and L=lim⁡n→∞∑k=1n40k3n4L = \lim_{n \to \infty} \sum_{k=1}^n \frac{40k^3}{n^4}. If the problem has multiple optimal solutions, what is the maximum value of ZZ?

22

Consider the optimization problem:

Maximize Z=2[x]+3yZ = 2[x] + 3y

subject to the constraints: 2x+3y≤182x + 3y \le 18 x≥0,y≥0x \ge 0, y \ge 0

where [x][x] denotes the greatest integer less than or equal to xx. Let SS be the set of all optimal solutions (x,y)(x, y) that maximize ZZ. Which of the following statements is true?

23

A discrete random variable XX takes values in {1,2}\{1, 2\} with the probability mass function: P(X=1)=14+12πarcsin⁡(sin⁡α)P(X=1) = \frac{1}{4} + \frac{1}{2\pi} \arcsin(\sin \alpha) P(X=2)=34−12πarccos⁡(cos⁡α)P(X=2) = \frac{3}{4} - \frac{1}{2\pi} \arccos(\cos \alpha) where α∈[0,2π]\alpha \in [0, 2\pi]. Let SS be the set of all values of α\alpha for which this defines a valid probability mass function. For a fixed α∈S\alpha \in S, consider the linear programming problem: Maximize Z=P(X=1)x+P(X=2)yZ = P(X=1) x + P(X=2) y subject to: 2x+y≤62x + y \le 6 x+3y≤9x + 3y \le 9 x≥0,y≥0x \ge 0, y \ge 0 Let M(α)M(\alpha) be the maximum value of ZZ for a given α\alpha. Find the minimum value of M(α)M(\alpha) over all α∈S\alpha \in S.

24

Let z=x+iyz = x + iy be a complex number satisfying x≥0x \ge 0, y≥0y \ge 0, and the inequality ∣z−2−4i∣+∣iz+12+4i∣≤10|z - 2 - 4i| + |iz + 12 + 4i| \le 10. Find the minimum value of the objective function f(z)=∣z−2−4i∣2+∣iz+12+4i∣2f(z) = |z - 2 - 4i|^2 + |iz + 12 + 4i|^2.

25

Let RR be the feasible region in the xyxy-plane defined by the system of inequalities: x+y≤10,x≤7,y≤8,2x+3y≤30,x≥0,y≥0x + y \le 10, \quad x \le 7, \quad y \le 8, \quad 2x + 3y \le 30, \quad x \ge 0, \quad y \ge 0 Consider the objective function Z=20−∣x−2y+5∣−∣2x+y−10∣Z = 20 - |x - 2y + 5| - |2x + y - 10|. If MM is the global maximum value of ZZ over the region RR, and it is attained at the point (x0,y0)(x_0, y_0), then the value of M+x0+y0M + x_0 + y_0 is

26

Let E1:x2−ax+8=0E_1: x^2 - a x + 8 = 0 and E2:x2−bx+32=0E_2: x^2 - b x + 32 = 0 be two quadratic equations with real coefficients having a positive common root rr. Let the non-common roots of E1E_1 and E2E_2 be α\alpha and β\beta respectively. It is given that α,r,β\alpha, r, \beta form a geometric progression in that order.

Consider the linear programming problem: Maximize Z=(a+b)x+(ab)yZ = (a+b)x + (ab)y subject to the constraints: αx+ry≤a\alpha x + r y \le a rx+βy≤br x + \beta y \le b x≥0,y≥0x \ge 0, y \ge 0

Find the maximum value of ZZ.

27

Let A={(x,y)∈R2:3x+4y≤25,  4x+3y≤25,  x+y≤7,  0≤x≤6,  0≤y≤6}A = \{ (x,y) \in \mathbb{R}^2 : 3x + 4y \le 25, \; 4x + 3y \le 25, \; x + y \le 7, \; 0 \le x \le 6, \; 0 \le y \le 6 \}. Let f:A→Bf: A \to B be a surjective function defined by f(x,y)=7x+7y+5f(x,y) = 7x + 7y + 5. Which of the following intervals represents the set BB?

28

Let cc be the number of positive integers tt satisfying (t−1)(t−5)t−3≤0\frac{(t-1)(t-5)}{t-3} \le 0, and dd be the number of positive integers tt satisfying t2−7t+12t−2≤0\frac{t^2 - 7t + 12}{t - 2} \le 0. Let SS be the region in the xyxy-plane defined by the inequalities x≥0x \ge 0, y≥0y \ge 0, [x]+[y]≤4[x] + [y] \le 4, and 2[x]−[y]≥12[x] - [y] \ge 1, where [⋅][ \cdot ] denotes the greatest integer function. If MM is the supremum of the objective function Z=cx+dyZ = cx + dy over the region SS, find the value of MM.

29

Let SS be the feasible region defined by the system of inequalities: x≥0,y≥0x \ge 0, \quad y \ge 0 x+y≤14x + y \le 14 24≤3x+4y≤24+5d24 \le 3x + 4y \le 24 + 5d where d>0d > 0 is the perpendicular distance between the parallel lines 3x+4y=243x + 4y = 24 and 3x+4y=24+5d3x + 4y = 24 + 5d. If the maximum value of the objective function Z=4x+5yZ = 4x + 5y on the region SS is 6262, find the area of the region SS.

30

Let XX be a discrete random variable uniformly distributed over the set {3,7,11,15}\{3, 7, 11, 15\}. Let μ\mu and σ2\sigma^2 denote the mean and variance of XX, respectively.

Consider the following linear programming problem: Maximize Z=σ2x+μyZ = \sigma^2 x + \mu y subject to the constraints: x+y≤34x + y \le 34 2x+y≤392x + y \le 39 5x+2y≤885x + 2y \le 88 9x+2y≤1449x + 2y \le 144 x≥0,y≥0x \ge 0, y \ge 0

The maximum value of ZZ is:

31

Let n^=13(i^+j^+k^)\hat{n} = \frac{1}{\sqrt{3}}(\hat{i} + \hat{j} + \hat{k}). A plane Π\Pi in R3\mathbb{R}^3 is defined by the equation r⃗⋅n^=23\vec{r} \cdot \hat{n} = 2\sqrt{3}. A feasible region SS on Π\Pi is bounded by the non-negativity conditions r⃗⋅i^≥0\vec{r} \cdot \hat{i} \ge 0, r⃗⋅j^≥0\vec{r} \cdot \hat{j} \ge 0, r⃗⋅k^≥0\vec{r} \cdot \hat{k} \ge 0, and the following projection constraints: r⃗⋅(i^+2j^)≤8\vec{r} \cdot (\hat{i} + 2\hat{j}) \le 8 r⃗⋅(2i^+3j^−k^)≤14\vec{r} \cdot (2\hat{i} + 3\hat{j} - \hat{k}) \le 14 Determine the maximum value of the objective function Z=r⃗⋅(10i^+24j^+8k^)Z = \vec{r} \cdot (10\hat{i} + 24\hat{j} + 8\hat{k}) for any position vector r⃗∈S\vec{r} \in S.

32

Let RR be the feasible region in the first quadrant bounded by the yy-axis, the line y=2y = 2, and the curve y=∫0x∣t2−1∣dty = \int_0^x |t^2 - 1| dt. If AA is the area of the region RR, find the maximum value of the objective function Z=4Ax−5yZ = 4A x - 5y over the region RR.

33

Let SS be the set of all real values of λ\lambda for which the linear programming problem:

Maximize Z=5x+2y+3zZ = 5x + 2y + 3z

subject to the equality constraints: 4y−2z=λ2−2λ4y - 2z = \lambda^2 - 2\lambda −2x+3z=1−3λ-2x + 3z = 1 - 3\lambda 3x−9y=23x - 9y = 2 x,y,z≥0x, y, z \ge 0

has a non-empty feasible region. The sum of all elements in SS is:

34

Let Sk={(x,y)∈R2:x2+y2≤25,  x2−y2≥k,  x≥0,  y≥0}S_k = \{ (x,y) \in \mathbb{R}^2 : x^2 + y^2 \le 25, \; x^2 - y^2 \ge k, \; x \ge 0, \; y \ge 0 \}. Let M(k)M(k) be the maximum value of the objective function Z=3x+4yZ = 3x + 4y subject to (x,y)∈Sk(x,y) \in S_k. Find the sum of all real values of kk for which M(k)=24M(k) = 24.

35

Let SS be the set of all ordered pairs (x,y)(x, y) of real numbers satisfying the system of equations: (8[x])+(8[y])=84\binom{8}{[x]} + \binom{8}{[y]} = 84 [x+y]=[x]+[y][x + y] = [x] + [y] x−y=[x]−[y]−15x - y = [x] - [y] - \frac{1}{5} 2x+3y=2[x]+3[y]+41102x + 3y = 2[x] + 3[y] + \frac{41}{10} where [t][t] denotes the greatest integer less than or equal to tt. Find the number of elements in SS.

36

Let AA be the origin and BB be the point representing the complex number 3+4i3+4i on the Argand plane. Let CC be a variable point representing the complex number ww such that ∣w−(8+6i)∣≤2|w - (8+6i)| \le 2. Let MM and mm be the maximum and minimum possible areas of △ABC\triangle ABC, respectively.

A factory produces quantities xx and yy (where x,y∈Rx, y \in \mathbb{R}) of two goods, X and Y. The profit per unit of X is MM and per unit of Y is mm. The production constraints are:

  1. The total quantity produced cannot exceed 10 units.
  2. The quantity of X produced must be at least the quantity of Y.
  3. At least 2 units of X and 1 unit of Y must be produced.

What is the maximum possible profit?

37

Let f:R→Rf: \mathbb{R} \to \mathbb{R} be defined by f(t)=t3−6t2+9tf(t) = t^3 - 6t^2 + 9t. Let SS be the set of all points (x,y)(x, y) in the Cartesian plane satisfying the following system of constraints:

  1. x≥0x \ge 0
  2. y−x≥1y - x \ge 1
  3. 2x+y≤82x + y \le 8
  4. f(t)f(t) is strictly increasing on the interval [x,y][x, y].

Define the objective function Z(x,y)=f(y)−f(x)y−xZ(x, y) = \frac{f(y) - f(x)}{y - x}. Find the maximum value of Z(x,y)Z(x, y) subject to (x,y)∈S(x, y) \in S.

38

Let RR be the region in 3D space consisting of all points P(x,y,z)P(x,y,z) that satisfy the following conditions:

  1. PP lies in the octant x≤0x \le 0, y≤0y \le 0, z≥0z \ge 0.
  2. The distance of PP from each of the coordinate planes is at most 2.
  3. The distance of PP from the plane x+2y+2z+1=0x + 2y + 2z + 1 = 0 is at most 1.

If the volume of the region RR is VV, find the value of 3V3V.

39

A manufacturing plant produces three types of components, with daily production quantities denoted by the column vector X=(xyz)X = \begin{pmatrix} x \\ y \\ z \end{pmatrix}. The production constraints are modeled by the matrix equation (A+I)X=B(A + I)X = B, where II is the 3×33 \times 3 identity matrix, B=(257)B = \begin{pmatrix} 2 \\ 5 \\ 7 \end{pmatrix}, and AA is a 3×33 \times 3 matrix such that A2=IA^2 = I. If it is given that AB=(−22119)A B = \begin{pmatrix} -2 \\ 21 \\ 19 \end{pmatrix}, and the profit function is P=10x+15y+20zP = 10x + 15y + 20z, what is the maximum possible daily profit?

40

Let the feasible region SS be defined by the inequality ∣x∣+∣y∣≤4|x| + |y| \le 4. A matrix MM is defined as M=(∣x∣−2∣y∣−2∣y∣−2∣x∣−2)M = \begin{pmatrix} |x| - 2 & |y| - 2 \\ |y| - 2 & |x| - 2 \end{pmatrix} If Z=det⁡(M)Z = \det(M), find the maximum value of the objective function ZZ for (x,y)∈S(x,y) \in S.

41

Let Z(x,y)Z(x,y) be the objective function defined by the line integral: Z(x,y)=∫(0,0)(x,y)((veu2v2+2u)du+(ueu2v2+2v)dv)Z(x,y) = \int_{(0,0)}^{(x,y)} \left( (v e^{u^2 v^2} + 2u)du + (u e^{u^2 v^2} + 2v)dv \right) where the integral is taken over any piecewise smooth curve connecting (0,0)(0,0) to (x,y)(x,y). Consider the linear programming problem: Maximize Z(x,y)Z(x,y) subject to the constraints: 2x+y≥42x + y \ge 4 x−y≤1x - y \le 1 x≥0,y≥0x \ge 0, y \ge 0 Which of the following represents the maximum value of Z(x,y)Z(x,y)?

42

Let RR be the feasible region in the first quadrant (x≥0,y≥0x \ge 0, y \ge 0) satisfying the following constraints:

  1. (∫−π/4π/4ln⁡(t+1+t2)dt)x+x+y≤4\left( \int_{-\pi/4}^{\pi/4} \ln\left(t + \sqrt{1+t^2}\right) dt \right) x + x + y \le 4
  2. xsin⁡α+ycos⁡α≤5x \sin \alpha + y \cos \alpha \le 5 for all α∈[0,2π]\alpha \in [0, 2\pi]

Consider the objective function Z(x,y)=∫0x2y4−t1+t2dtZ(x,y) = \int_{0}^{x^2 y} \frac{4-t}{1+t^2} dt. The maximum value of Z(x,y)Z(x,y) over the region RR is:

43

Let SS be the line segment defined by the equation x+y=10x + y = 10 for 5≤x≤85 \le x \le 8. Given two points A(4,4)A(4,4) and B(2,6)B(2,6), find the minimum value of PA+PBPA + PB as the point PP varies over the segment SS.

44

Let XX be a discrete random variable taking values −1,0,-1, 0, and 11 with probabilities p1,p2,p_1, p_2, and p3p_3 respectively. It is given that p2≥15p_2 \ge \frac{1}{5} and ∣E[X]∣≤25|E[X]| \le \frac{2}{5}, where E[X]E[X] denotes the expected value of XX. The maximum possible variance of XX is

45

Let A=(1102)A = \begin{pmatrix} 1 & 1 \\ 0 & 2 \end{pmatrix} and B=(1124−20)B = \begin{pmatrix} 11 & 24 \\ -2 & 0 \end{pmatrix} be two matrices. A feasible region RR in the xyxy-plane is defined by the system of inequalities: x≥0x \ge 0, y≥0y \ge 0, and x+214y≤1x + 214y \le 1. The region RR is transformed into a new region R′R' by the linear transformation T(v)=MvT(\mathbf{v}) = M\mathbf{v}, where the transformation matrix is given by M=(A+B)2−(A2+B2)M = (A+B)^2 - (A^2+B^2). What is the area of the region R′R'?

46

Let T(t)T(t) be a triangle in the xyxy-plane with vertices A(t,0)A(t, 0), B(0,t−1)B(0, t-1), and C(∣t∣,∣t−1∣)C(|t|, |t-1|). If S(t)S(t) denotes the area of the triangle T(t)T(t), find the value of 12∫−12S(t)dt12 \int_{-1}^{2} S(t) dt

47

Let RR be the feasible region in R3\mathbb{R}^3 defined by the following system of inequalities: x≥0,y≥0,z≥0x \ge 0, y \ge 0, z \ge 0 2x+y+3z≤122x + y + 3z \le 12 x+3y+2z≤12x + 3y + 2z \le 12 3x+4y+5z≥243x + 4y + 5z \ge 24 If LL is the maximum distance between any two points in RR, find the value of 49L249 L^2.

48

Let RR be the feasible region in the xyxy-plane defined by the inequalities x≥0x \ge 0, y≥0y \ge 0, and x+y≤25x + y \le 25. Find the maximum value of the objective function Z(x,y)=2x+y−3∣x−4∣2/3Z(x,y) = 2x + y - 3|x-4|^{2/3} over the region RR.

49

Let F⃗(x)=∫(2xi^+2xj^)dx\vec{F}(x) = \int (2x \hat{i} + 2x \hat{j}) dx. The constant of integration is K⃗=Ci^−Cj^\vec{K} = C \hat{i} - C \hat{j}, where CC is an integer. Let V⃗1=F⃗(1)\vec{V}_1 = \vec{F}(1) and V⃗2=F⃗(2)\vec{V}_2 = \vec{F}(2). Consider the Linear Programming Problem: Maximize Z=x+yZ = x + y Subject to: r⃗⋅V⃗1≥12\vec{r} \cdot \vec{V}_1 \ge 12 r⃗⋅V⃗2≤18\vec{r} \cdot \vec{V}_2 \le 18 x≥0,y≥0x \ge 0, y \ge 0 where r⃗=xi^+yj^\vec{r} = x \hat{i} + y \hat{j}. Let SS be the set of all integers C∈[−10,10]C \in [-10, 10] for which the feasible region is non-empty. Find the number of elements in SS.

50

Let RR be the feasible region in the first quadrant (x≥0,y≥0x \ge 0, y \ge 0) defined by the inequalities: x2+(y−602)2≤2(y−302)\sqrt{x^2 + (y - 60\sqrt{2})^2} \le \sqrt{2} (y - 30\sqrt{2}) {x32}≤1132\left\{ \frac{x}{32} \right\} \le \frac{11}{32} where {⋅}\{ \cdot \} denotes the fractional part function. Find the minimum value of the objective function Z=13y−5xZ = 13y - 5x over the region RR.

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