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Mathematics • Class 12

Application of Integrals - Class 12

Master Calculus — Applications of Integrals 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 focuses on the real-world applications of integrals. It includes methods for finding areas under curves, areas between two curves, and their applications in solving problems related to physics and engineering.

Why This Chapter Matters

  • The application of integrals is a critical skill for solving real-world problems in fields like engineering, physics, and economics. This chapter helps you understand how to calculate areas and solve problems involving integration in practical contexts.

Real-Life Applications

  • Calculating areas under curves and between curves in engineering and physics.
  • Modeling problems in economics, such as cost and revenue analysis.
  • Solving problems related to motion and energy in physics.

Skills You Will Learn

  • Using definite integrals to calculate areas under curves and between two curves.
  • Applying integrals to solve real-world problems in various fields.
  • Developing problem-solving skills in calculus and its applications.

Core Concepts to Master

The Sign-Consistency Principle

Total area requires integrating the absolute value; splitting limits at roots of the function is mandatory.

Axis of Integration Selection

Choose dx or dy based on the easier boundary function representation to minimize integral complexity.

Horizontal vs Vertical Strips

Width of the strip must be perpendicular to the axis of integration; orientation dictates integral variable.

Intersection Point Accuracy

Algebraic errors in finding intersection coordinates propagate through the entire calculation; always verify against graphs.

Symmetry Utilization

Use even/odd properties or quadrant symmetry to compute one part and multiply; prevents calculation fatigue.

Inverse Function Integration

Calculating area bounded by y-axis using x=f(y) is often faster than converting to y=f(x).

Bounded vs Unbounded Regions

Distinguish between 'area of region' and 'definite integral'; negative values represent orientation, not physical area.

The Modulus Trap

Functions involving |f(x)| require splitting the domain based on the sign change of f(x).

Parametric Curve Area

Convert dx to (dx/dt)dt and dy to (dy/dt)dt; maintain consistent parameter bounds for the integral.

Region Ambiguity

If multiple regions satisfy the inequalities, identify the specific intersection defined by the problem statement.

Standard Ellipse/Circle Area

Use 4 times the area in the first quadrant for efficiency; avoid integrating over the full 2π.

Compound Function Boundaries

Graph piecewise functions carefully; the area is the sum of integrals over disjoint domain intervals.

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.

The Sign-Consistency Principle
Algebraic-Trigonometric Graphical Mapping
Variable Transformation Substitution
The Sign-Consistency Principle
Concavity Analysis
Step Function Discontinuities
Rate of Change Dependency
The Sign-Consistency Principle
Condition for Common Roots
Geometry of Complex Inequalities
The Sign-Consistency Principle
Ellipse Auxiliary Circle
Polar and Pole Duality
Symmetric vs Non-symmetric form
The Sign-Consistency Principle
Fundamental Theorem of Calculus
Modulus Function Breakdown
The Modulus Trap
The Sign-Consistency Principle
Homogeneous Function Homogeneity
The Zero-Factor Cancellation Trap
The Sign-Consistency Principle
Lagrange Identity
Dot Product Projection Sign
The Sign-Consistency Principle
Newton-Leibniz Formula with variable limits
Greatest Integer Function Traps
The Sign-Consistency Principle
Scalar Triple Product Volume Logic
Dot Product Projection Sign
Scalar Multiplication Geometric Scaling
The Sign-Consistency Principle
Standard Ellipse/Circle Area
Even Multiplicity Roots
Greatest Integer Function Traps
Axis of Integration Selection
Area of Triangle via Determinants
Coplanarity Condition
Axis of Integration Selection
Bounded vs Unbounded Regions
Improper Integrals
Axis of Integration Selection
Compound Function Boundaries
Locus Problems via Transformation
The Sign-Consistency Principle
Axis of Integration Selection
Geometric Interpretation of Cross Product
Collinearity and Coplanarity
Line lying in a plane
Axis of Integration Selection
Hyperbola Conjugate Axes
Asymptote Geometry
Closed vs Open Intervals
Axis of Integration Selection
Leibniz Rule for Differentiation under Integral
Global Extrema on Intervals
Axis of Integration Selection
Newton-Leibniz Formula with variable limits
Second Order Derivative Continuity
Limit Existence at Discontinuity
Axis of Integration Selection
Parametric Curve Area
Modulus Function Breakdown
Horizontal vs Vertical Strips
Angle between two planes
Image of a point in a plane
Angle Bisector Direction
Horizontal vs Vertical Strips
Axis of Integration Selection
Logarithmic Differentiation Domain
Horizontal vs Vertical Strips
Differentiation of Determinants
Row/Column Exchange Parity
Linear Dependency of Rows
Horizontal vs Vertical Strips
Homogeneous Function Homogeneity
Composition Continuity
Differentiability vs Continuity
Horizontal vs Vertical Strips
Intersection Point Accuracy
Tangent/Normal Slope Interplay
Horizontal vs Vertical Strips
Linearity and Partitioning
Domain Constraint Intersections
Horizontal vs Vertical Strips
Parametric Form Manipulation
Parametric Derivative Endpoint Trap
Horizontal vs Vertical Strips
Parametric Form Manipulation
Polar and Pole Duality
Denominator Restriction
Horizontal vs Vertical Strips
Symmetry and Periodicity
Signum Function Discontinuity
Intersection Point Accuracy
Characteristic Equation
Linear Dependency of Rows
Intersection Point Accuracy
Equation of plane through intersection
Projection vs. Coordinate
Intersection Point Accuracy
General Solution Principal Values
The Sum-Difference Formula Constraints
Intersection Point Accuracy
Geometric Interpretation
Point of Inflection Conditions
Intersection Point Accuracy
Implicit Differentiation Rate
Logarithmic Differentiation Domain
Intersection Point Accuracy
Intersection of Conics
Modulus Inequality Logic
Cross Multiplication Trap
Intersection Point Accuracy
Intersection of Conics
Modulus Inequality Logic
Limit Existence at Discontinuity
Intersection Point Accuracy
Parametric Curve Area
Algebraic-Trigonometric Graphical Mapping
General Solution Principal Values
Symmetry Utilization
Definite Integral Properties (King's Property)
The Quadrant Adjustment Logic
Symmetry Utilization
Global Extrema on Intervals
Critical Point vs Stationary Point
Symmetry Utilization
Modulus Function Symmetry
Modulus Sign Dependency
Symmetry Utilization
Reflective Property
Intersection of Conics
Symmetry Utilization
Skew-Symmetric Determinant
Linear Dependency of Rows
Inverse Function Integration
Euler's Form and Rotations
Geometrical Interpretation of Modulus
Inverse Function Integration
Monotonicity and Boundedness
Differentiability vs Continuity
Modulus Function Symmetry
Inverse Function Integration
Substitution (Change of Variable)
Intersection Point Accuracy
Extraneous Solution Rejection
Inverse Function Integration
Variable Transformation Substitution
Inequalities in Definite Integrals
Bounded vs Unbounded Regions
Area of Triangle via Determinants
Minors and Cofactors Sign Convention
Bounded vs Unbounded Regions
Homogeneous Function Homogeneity
Even and Odd Function Symmetry
Bounded vs Unbounded Regions
Horizontal vs Vertical Strips
Modulus Inequality Logic
Bounded vs Unbounded Regions
Parametric Curve Area
Even Multiplicity Roots
Bounded vs Unbounded Regions
Rectangular Hyperbola
Greatest Integer Function Traps
The Modulus Trap
Area of Triangle via Determinants
Determinant Scaling Property
The Modulus Trap
Composition Continuity
Wavy Curve (Method of Intervals)
The Modulus Trap
Geometrical Interpretation of Modulus
Lagrange Identity
The Modulus Trap
Homogeneous Function Homogeneity
Even and Odd Function Symmetry
Wavy Curve (Method of Intervals)
Parametric Curve Area
Integral as the Limit of a Sum
Squeeze Theorem (Sandwich Theorem)
L'Hopital's Pitfall
Parametric Curve Area
Intersection of Conics
Polar and Pole Duality
Bounded vs Unbounded Regions
Parametric Curve Area
Scalar Multiplication Geometric Scaling
Direction Cosines constraint
Parametric form pitfalls
Parametric Curve Area
Symmetry Utilization
Modulus Function Symmetry
Polynomial Function Parity
Parametric Curve Area
Variable Separable Constraints
Logarithmic Integration Modulus
Parametric Derivative Endpoint Trap
Region Ambiguity
Homogeneous Function Homogeneity
Differentiation of Determinants
Region Ambiguity
Latus Rectum Geometry
Condition of Tangency
Region Ambiguity
Rectangular Hyperbola
Step Function Discontinuities
The Sign-Consistency Principle
Region Ambiguity
Scalar Triple Product Volume Logic
Scalar Multiplication Geometric Scaling
Region Ambiguity
Unbounded Region Trap
Signum Function Discontinuity
Standard Ellipse/Circle Area
Chord of Contact Logic
Integration Constant Trap
Standard Ellipse/Circle Area
Geometric Interpretation (Differential Equations)
Bernoulli Equation Transformation
Standard Ellipse/Circle Area
Inverse Function Integration
Inverse Function Derivative
Parametric Derivative Endpoint Trap
Standard Ellipse/Circle Area
Leibniz Rule for Differentiation under Integral
Greatest Integer Function (GIF)
Principal Value Branch Boundaries
Compound Function Boundaries
Composition Continuity
The Zero-Factor Cancellation Trap
Inverse Function Periodicity
Compound Function Boundaries
Determinant as Geometric Area/Volume
Equation of plane through intersection
Parametric form pitfalls
Compound Function Boundaries
Integration by Parts (LIATE Rule)
Integration Constant Trap
Square Root and Modulus Logic
Compound Function Boundaries
Inverse Function Derivative
Logarithmic Differentiation Domain
The Zero-Factor Cancellation Trap
Compound Function Boundaries
Maximum/Minimum of Quadratic Expressions
Cross Multiplication Trap
Concavity Analysis

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

IB Mathematics AA HL

International · Curriculum · IB Diploma

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 f(x)=e[x]∫0xsgn(sin⁡(πt))dtf(x) = e^{[x]} \int_{0}^{x} \text{sgn}(\sin(\pi t)) dt, where [x][x] denotes the greatest integer less than or equal to xx. Evaluate the definite integral ∫0202f′(x)dx\int_{0}^{202} f'(x) dx, where the integration is performed over the points of differentiability of f(x)f(x).

2

Let w∈Cw \in \mathbb{C} satisfy ∣w+2∣≤1|w + 2| \le 1. If the equations z2+wz+1+i=0z^2 + wz + 1 + i = 0 and z2+iz+w+1=0z^2 + iz + w + 1 = 0 share at least one common root, let f(x)=x2+Re(w)x+Im(w)f(x) = x^2 + \text{Re}(w)x + \text{Im}(w) for x∈Rx \in \mathbb{R}. Find the area of the region bounded by the curves y=∣f(x)∣y = |f(x)| and y=2y = 2.

3

Let a⃗=3i^−j^\vec{a} = \sqrt{3}\hat{i} - \hat{j} and b⃗(x)=(sin⁡x)i^+(cos⁡x)j^+(x2ex)k^\vec{b}(x) = (\sin x)\hat{i} + (\cos x)\hat{j} + (x^2 e^x)\hat{k} be two vectors. Consider the integral I=∫0π∣a⃗∣2∣b⃗(x)∣2−∣a⃗×b⃗(x)∣2 dxI = \int_0^\pi \sqrt{|\vec{a}|^2 |\vec{b}(x)|^2 - |\vec{a} \times \vec{b}(x)|^2} \, dx The value of II is:

4

Let y=y(x)y = y(x) be the continuously differentiable solution to the differential equation xdydx=y+x2−y2,x≥1x \frac{dy}{dx} = y + \sqrt{x^2 - y^2}, \quad x \ge 1 satisfying the initial condition y(1)=0y(1) = 0. Find the value of the integral ∫1eπy(x) dx\int_{1}^{e^\pi} y(x) \, dx.

5

Evaluate the integral I=∫031(1+x2)2arcsin⁡(2x1+x2)dxI = \int_{0}^{\sqrt{3}} \frac{1}{(1+x^2)^2} \arcsin\left(\frac{2x}{1+x^2}\right) dx

6

Consider the parametric curve defined by x(t)=t2−2tx(t) = t^2 - 2t and y(t)=∣t∣(3−t)y(t) = |t|(3 - t) for t∈Rt \in \mathbb{R}. The curve intersects itself at a single point, forming a closed loop. The area of the region enclosed by this loop is:

7

Let mm and MM be the global minimum and global maximum values of the function f(x)=x3−3x2+2f(x) = x^3 - 3x^2 + 2 on the interval [−1,4][-1, 4]. Let A(t)A(t) be the area of the region in the xyxy-plane bounded by the curve y=2x3+2x−2y = 2x^3 + 2x - 2, the yy-axis, and the horizontal line y=ty = t (for t≥−2t \ge -2). Find the value of 15∫mM(A′(t))2 dt15 \int_{m}^{M} (A'(t))^2 \, dt

8

Let A(1,2,3)A(1, 2, 3), B(2,−1,1)B(2, -1, 1), and C(−1,1,2)C(-1, 1, 2) be three points in R3\mathbb{R}^3. The planar triangle ABCABC is rotated by an angle of 2π2\pi about the line L:x=y=zL: x = y = z to generate a solid of revolution. If the volume of this solid is VV, then VV is equal to:

9

Consider the improper iterated integrals over the unbounded region [1,∞)×[1,∞)[1, \infty) \times [1, \infty): I1=∫1∞(∫1∞x2−y2(x2+y2)2 dy) dxI_1 = \int_1^\infty \left( \int_1^\infty \frac{x^2-y^2}{(x^2+y^2)^2} \, dy \right) \, dx I2=∫1∞(∫1∞x2−y2(x2+y2)2 dx) dyI_2 = \int_1^\infty \left( \int_1^\infty \frac{x^2-y^2}{(x^2+y^2)^2} \, dx \right) \, dy Which of the following represents the ordered pair (I1,I2)(I_1, I_2)?

10

Let CC be the locus of points (x,y)(x,y) defined parametrically by x=2sin⁡tx = 2\sin t and y=2cos⁡2t+2y = 2\cos 2t + 2 for t∈[0,3π2]t \in \left[0, \frac{3\pi}{2}\right]. Find the area of the region bounded by CC and the x-axis.

11

Let R={(x,y)∈R2:−10≤y≤14,min⁡(f(y),g(y))≤x≤max⁡(f(y),g(y))}R = \left\{ (x, y) \in \mathbb{R}^2 : -10 \le y \le 14, \min(f(y), g(y)) \le x \le \max(f(y), g(y)) \right\}, where f(y)=sgn(y){y}−{y}2f(y) = \text{sgn}(y) \sqrt{\{y\} - \{y\}^2} and g(y)=12−∣{y}−12∣g(y) = \frac{1}{2} - \left| \{y\} - \frac{1}{2} \right|. Here, {y}\{y\} denotes the fractional part of yy and sgn(y)\text{sgn}(y) denotes the signum function. The area of the region RR is:

12

Let DD be the region in the first quadrant bounded by the yy-axis and the curves y=tan⁡−1xy = \tan^{-1} x and y=cot⁡−1xy = \cot^{-1} x. Evaluate the double integral: I=∬Dxsin⁡4y+cos⁡4y dx dyI = \iint_D \frac{x}{\sin^4 y + \cos^4 y} \, dx \, dy

13

Let C1C_1 be the parabola y2=4(x+2)y^2 = 4(x+2). Let C2C_2 be a continuous curve passing through the point (7,6)(7,6) such that for all points (x,y)(x,y) on C2C_2 with x≠1x \neq 1, the slope of its normal is given by y1−x\frac{y}{1-x}. If AA is the area of the region bounded by C1C_1 and C2C_2, then the value of AA is

14

Let CC be the curve defined by the equation ln⁡x=yln⁡y+ln⁡(1+ln⁡y)\ln x = y \ln y + \ln(1 + \ln y). Let RR be the finite region in the first quadrant bounded by the curve CC, the yy-axis, and the line y=1y=1. The area of the region RR is

15

Let x1x_1 and x2x_2 (x1<x2x_1 < x_2) be the abscissae of the intersection points of the parabola P:y=3x2−32P: y = 3x^2 - \frac{3}{2} and the hyperbola H:4y2−4x2=5H: 4y^2 - 4x^2 = 5 that lie in the region y<0y < 0. Evaluate the integral I=∫01∣x2−x22∣ dx−5x25I = \int_{0}^{1} \left| x^2 - x_2^2 \right| \, dx - 5x_2^5

16

Consider the curves C1C_1 and C2C_2 defined parametrically by C1:x=t+sin⁡t,y=cos⁡tC_1: x = t + \sin t, y = \cos t and C2:x=t+sin⁡t,y=cos⁡2tC_2: x = t + \sin t, y = \cos 2t. Let PP be the point of intersection of C1C_1 and C2C_2 on the yy-axis, and QQ be their next point of intersection with x>0x > 0. The area of the region bounded by C1C_1 and C2C_2 between PP and QQ is:

17

The curves C1:log⁡2(x−2)+log⁡2(y−1)=2C_1: \log_2(x-2) + \log_2(y-1) = 2 and C2:x−y=1C_2: x - y = 1 intersect at a real point PP. A third curve C3C_3 is defined implicitly by the equation x3+y3−5xy−2x−6y=5x^3 + y^3 - 5xy - 2x - 6y = 5 Find the slope of the tangent to the curve C3C_3 at the point PP.

18

Let P1P_1 be the plane passing through the point (1,1,1)(1, 1, 1) and the line of intersection of the planes x+y+z=1x + y + z = 1 and x−y+z=3x - y + z = 3. Let CC be the solid cylinder x2+y2≤4x^2 + y^2 \le 4. The plane P1P_1 intersects the cylinder CC in an elliptical region RR. If AA is the area of the orthogonal projection of the region RR onto the plane x+y+2z=0x + y + \sqrt{2}z = 0, then find AA.

19

Evaluate the definite integral: ∫02∣∣x2−2∣−1∣ dx\int_{0}^{2} \left| |x^2 - 2| - 1 \right| \, dx

20

Let SS be the region in the xyxy-plane defined by S={(x,y):x2+y2≤4 and (y−[x])(x3−x2−x+1)≤0}S = \left\{ (x,y) : x^2 + y^2 \le 4 \text{ and } (y - [x])(x^3 - x^2 - x + 1) \le 0 \right\} where [x][x] denotes the greatest integer less than or equal to xx. The area of the region SS is:

21

Let EE be the ellipse x2+3y2=12x^2 + 3y^2 = 12. The polar of the point P(6,2)P(6, 2) with respect to EE is the line LL. Let LL be represented by the equation f(x,y)=0f(x,y) = 0, where f(x,y)f(x,y) is a linear polynomial in xx and yy with coprime integer coefficients such that f(0,0)>0f(0,0) > 0.

Consider the region R={(x,y)∈R2:x2+3y2≤12 and f(x,y)≥0}\mathcal{R} = \{ (x,y) \in \mathbb{R}^2 : x^2 + 3y^2 \le 12 \text{ and } f(x,y) \ge 0 \}.

The area of the region R\mathcal{R} is:

22

Let a⃗,b⃗,c⃗\vec{a}, \vec{b}, \vec{c} be three non-coplanar vectors such that [a⃗,b⃗,c⃗]=3[\vec{a}, \vec{b}, \vec{c}] = \sqrt{3}. A varying vector p⃗(t)\vec{p}(t) is defined as p⃗(t)=(sin⁡t)a⃗+(sin⁡t−cos⁡t)b⃗+(cos⁡2t)c⃗\vec{p}(t) = (\sin t)\vec{a} + (\sin t - \cos t)\vec{b} + (\cos 2t)\vec{c} for t∈[0,2π]t \in [0, 2\pi]. Let V(t)V(t) be the volume of the parallelepiped formed by the vectors a⃗+b⃗\vec{a}+\vec{b}, b⃗+c⃗\vec{b}+\vec{c}, and p⃗(t)\vec{p}(t). If SS is the set of all t∈[0,2π]t \in [0, 2\pi] such that the angle between p⃗(t)\vec{p}(t) and (a⃗+b⃗)×(b⃗+c⃗)(\vec{a}+\vec{b}) \times (\vec{b}+\vec{c}) is obtuse, find the value of ∫SV(t)dt\int_S V(t) dt.

23

Let f(x)=∫0x∣t2−1∣dtf(x) = \int_0^x |t^2 - 1| dt. Find the area of the region bounded by the curve y=x⌊f′′(x)⌋y = x \lfloor f''(x) \rfloor, the x-axis, and the ordinates x=0x = 0 and x=2x = 2, where ⌊⋅⌋\lfloor \cdot \rfloor denotes the greatest integer function.

24

Let a⃗=2i^+j^−k^\vec{a} = 2\hat{i} + \hat{j} - \hat{k} and b⃗=i^+2j^+k^\vec{b} = \hat{i} + 2\hat{j} + \hat{k}. A planar region SS in R3\mathbb{R}^3 consists of all points whose position vector r⃗\vec{r} satisfies r⃗⋅(a⃗×b⃗)=0\vec{r} \cdot (\vec{a} \times \vec{b}) = 0, ∣r⃗×a⃗∣≤63|\vec{r} \times \vec{a}| \le 6\sqrt{3}, and ∣r⃗×b⃗∣≤93|\vec{r} \times \vec{b}| \le 9\sqrt{3}. If RR is the orthogonal projection of the region SS onto the xyxy-plane, find the value of the integral ∬R(x−y)2 dx dy\iint_R (x - y)^2 \,dx\,dy.

25

Let RR be the region in the first quadrant bounded by the hyperbola y2−x2=1y^2 - x^2 = 1, its asymptote y=xy = x, and the yy-axis. If the region RR is revolved about the line y=xy = x, the volume of the resulting solid is VV. Find VV.

26

Let F(x)=∫0x(∫0ysgn(y−2t)et2dt)dyF(x) = \int_{0}^{x} \left( \int_{0}^{y} \text{sgn}(y - 2t) e^{t^2} dt \right) dy for x>0x > 0. Find the value of F′′(2)F''(2).

27

Let I=∫01∫x2xarcsin⁡(sin⁡(πyx))dy dxI = \int_{0}^{1} \int_{x^2}^{x} \arcsin\left(\sin\left(\frac{\pi y}{x}\right)\right) dy \, dx. If I=pπqI = \frac{p\pi}{q}, where pp and qq are coprime positive integers, find the value of p+qp+q.

28

Let CC be a curve defined parametrically by x=t2,y=2tx = t^2, y = 2t for t∈Rt \in \mathbb{R}. Let LL be the polar line of the point P(−1,0)P(-1, 0) with respect to CC. If RR is the finite region bounded by CC and LL, evaluate the integral: I=∬Ry2(x+1)31−x dx dyI = \iint_R \frac{y^2}{(x+1)^3 \sqrt{1-x}} \,dx\,dy

29

Let D(x)=∣log⁡22log⁡24log⁡28x3x2xsec⁡2(π4)tan⁡2(π4)3∣D(x) = \begin{vmatrix} \log_2 2 & \log_2 4 & \log_2 8 \\\\ x^3 & x^2 & x \\\\ \sec^2\left(\frac{\pi}{4}\right) & \tan^2\left(\frac{\pi}{4}\right) & 3 \end{vmatrix} and f(x)=D′(x)f(x) = D'(x).

Find the area of the region bounded by the curves y=f(x)y = f(x) and y=−3x2+6x+3y = -3x^2 + 6x + 3.

30

Let P1:3x+4y+5z=14P_1: 3x + 4y + 5z = 14 and P2:4x+3y−5z=14P_2: 4x + 3y - 5z = 14 be two planes. Let Π\Pi be the plane bisecting the obtuse angle between P1P_1 and P2P_2. Let M(h,k,l)M(h, k, l) be the image of the point N(2,0,0)N(2, 0, 0) in the plane Π\Pi.

Let RR be the region in the xyxy-plane bounded by the parabola x=y2−yx = y^2 - y and the line x=kyx = ky. Find the area of the region RR.

31

Let SS be the set of all points (x,y)(x, y) in the Cartesian plane that satisfy the system of equations: 3x2+4y2=163x^2 + 4y^2 = 16 5x2−2y2=185x^2 - 2y^2 = 18 Find the number of integer values of k∈[1,10]k \in [1, 10] such that the inequality k∣x∣−12∣y∣−2≤3\frac{k|x| - 12}{|y| - 2} \le 3 holds true for all points (x,y)∈S(x, y) \in S.

32

Let f(x)=x4−6x3+12x2−8x+3f(x) = x^4 - 6x^3 + 12x^2 - 8x + 3. If LL is the tangent line to the curve y=f(x)y = f(x) at its point of inflection with the smaller xx-coordinate, then the area of the region bounded by the curve y=f(x)y = f(x) and the line LL is

33

Let C1C_1 be the locus of points (x,y)(x,y) for x>0x > 0 such that the matrix equation (x1x2x)(uv)=(yx+2)\begin{pmatrix} x & 1 \\ x^2 & x \end{pmatrix} \begin{pmatrix} u \\ v \end{pmatrix} = \begin{pmatrix} y \\ x+2 \end{pmatrix} has at least one solution for (u,v)(u,v). Let C2C_2 be the locus of points (x,y)(x,y) for x>0x > 0 such that the matrix M=(y22x)M = \begin{pmatrix} y & 2 \\ 2 & x \end{pmatrix} has λ=0\lambda = 0 as an eigenvalue. If RR is the region in the first quadrant bounded by C1C_1, C2C_2, and the line x=1x = 1, find the area of RR.

34

Let AA be the area of the region bounded by the curves y=sin⁡−1(sin⁡x)y = \sin^{-1}(\sin x) and y=cos⁡−1(sin⁡x)y = \cos^{-1}(\sin x) for x∈[0,2π]x \in [0, 2\pi]. The value of AA is:

35

Consider the region R={(x,y)∈R2:∣y∣≤e−∣x∣sin⁡(πx), −1≤x≤1}R = \{ (x, y) \in \mathbb{R}^2 : |y| \le e^{-|x|} \sin(\pi x), \ -1 \le x \le 1 \}. The area of RR is

36

Evaluate the definite integral: I=∫02πx1−cos⁡(2x)2(1+cos⁡2x)dxI = \int_{0}^{2\pi} \frac{x \sqrt{1 - \cos(2x)}}{\sqrt{2} (1 + \cos^2 x)} dx

37

A curve C1C_1 passing through the origin has the property that any ray of light moving parallel to the xx-axis reflects off C1C_1 and passes through the point S(1,0)S(1,0). Let C2C_2 be an ellipse whose foci are the origin and SS, and whose major axis has length 22. If AA is the area of the region bounded by C1C_1 and C2C_2 containing the point (12,0)\left(\frac{1}{2}, 0\right), then AA equals:

38

Let MM be the global maximum value of the function g(t)=∫0t3(1−s2)dsg(t) = \int_0^t 3(1 - s^2) ds on the interval [−2,2][-2, 2]. Let AA be the area of the region bounded by the curve y=∣x3−3x∣y = |x^3 - 3x| and the line y=My = M. Find the value of AA.

39

Let M(x)=(x3−λxe∣x∣sin⁡xcos⁡x−e∣x∣sin⁡xx3−λx1+x2−cos⁡x−1+x2x3−λx)M(x) = \begin{pmatrix} x^3 - \lambda x & e^{|x|} \sin x & \cos x \\ -e^{|x|} \sin x & x^3 - \lambda x & \sqrt{1+x^2} \\ -\cos x & -\sqrt{1+x^2} & x^3 - \lambda x \end{pmatrix}, where λ\lambda is a real parameter. Let f(x)=det⁡(M(x))f(x) = \det(M(x)). If the rows of M(x)M(x) are linearly dependent at x=2x = 2, then the value of the integral ∫−22(f(x)2+cos⁡x+3λ2x2)dx\int_{-2}^{2} \left( \frac{f(x)}{2 + \cos x} + \frac{3\lambda}{2} x^2 \right) dx is equal to:

40

Let f:R→Rf: \mathbb{R} \to \mathbb{R} be a strictly increasing continuous function defined as f(x)=x3+72x+∫0x∣t−2∣dtf(x) = x^3 + \frac{7}{2}x + \int_0^x |t - 2| dt If I=∫0247f−1(x)dxI = \int_{0}^{247} f^{-1}(x) dx, then the value of 3I3I is equal to:

41

Let f:(−∞,3]→(−∞,5]f: (-\infty, 3] \to (-\infty, 5] be defined by f(x)=−x2+6x−4f(x) = -x^2 + 6x - 4. If x0x_0 is the unique real root of the equation f(x)=f−1(x)f(x) = f^{-1}(x), evaluate the integral I=∫−4x0f−1(x)dxI = \int_{-4}^{x_0} f^{-1}(x) dx

42

Let S={z∈C:∣z−Re(z)∣≤Re(z)eRe(z),0≤Re(z)≤2}S = \{ z \in \mathbb{C} : |z - \text{Re}(z)| \le \text{Re}(z) e^{\text{Re}(z)}, 0 \le \text{Re}(z) \le 2 \}. Let S′S' be the image of SS under the transformation w=zeiπ/2w = z e^{i\pi/2}, and let S′′={w∈S′:Re(w)≥0}S'' = \{ w \in S' : \text{Re}(w) \ge 0 \}. If AA denotes the area of the region S′′S'' in the complex plane, and B=∫02e2f−1(x)dxB = \int_0^{2e^2} f^{-1}(x) dx where f(x)=xexf(x) = x e^x for x≥0x \ge 0, find the value of 3A−B3A - B.

43

Let I=∫0πxcos⁡x1+sin⁡2x dxI = \int_{0}^{\pi} \frac{x \cos x}{1 + \sin^2 x} \, dx. Which of the following statements is correct?

44

Let RR be the region in the first quadrant bounded by the curve y=[6x]y = \left[ \frac{6}{x} \right], the x-axis, and the vertical lines x=1x = 1 and x=4x = 4, where [t][t] denotes the greatest integer less than or equal to tt. If AA is the area of the region RR, then the value of 10A10A is:

45

Let RR be the region in the xyxy-plane defined by the inequality ∣x2−2x∣+∣y−x∣≤1|x^2 - 2x| + |y - x| \le 1. The area of the region RR is

46

Let RR be the region enclosed by the parametric curve x(t)=t3−3tx(t) = t^3 - 3t and y(t)=(t2−1)2(t2−3)y(t) = (t^2 - 1)^2 (t^2 - 3), where the parameter tt satisfies the inequality (t2−1)2(t2−3)≤0(t^2 - 1)^2 (t^2 - 3) \le 0. The area of the region RR is

47

Let f(x,y)f(x, y) be a polynomial function satisfying f(tx,ty)=t5f(x,y)f(tx, ty) = t^5 f(x, y) for all t,x,y∈Rt, x, y \in \mathbb{R}. Given f(1,y)=1−5y2+4y4f(1, y) = 1 - 5y^2 + 4y^4, evaluate the integral I=∫−33(∣f(x,1)∣+f(x,1))dxI = \int_{-3}^{3} \left( |f(x, 1)| + f(x, 1) \right) dx

48

Let f(x)=∣x∣f(x) = |x| and g(x)=x∣x−2∣−1g(x) = x|x-2| - 1. Evaluate the integral ∫03f(g(x)) dx\int_{0}^{3} f(g(x)) \, dx

49

Let MM be a 3×33 \times 3 matrix with real entries such that det⁡(M)=2\det(M) = 2, and let A=adj(M)A = \text{adj}(M). Let OO be the origin (0,0)(0,0). For any real number xx, let P(x)P(x) be the point (x,det⁡(xA))(x, \det(xA)) and QQ be the point (2,det⁡(2A))(2, \det(2A)) in the xyxy-plane. If S(x)S(x) denotes the area of the triangle OP(x)QOP(x)Q, find the value of the integral ∫−12S(x) dx\int_{-1}^{2} S(x) \, dx

50

Let a⃗(x)\vec{a}(x) and b⃗(x)\vec{b}(x) be two continuous vector-valued functions in R3\mathbb{R}^3 such that for all x∈Rx \in \mathbb{R}, ∣a⃗(x)∣2=2x4+1|\vec{a}(x)|^2 = 2x^4 + 1, ∣b⃗(x)∣2=x2+2|\vec{b}(x)|^2 = x^2 + 2, and a⃗(x)⋅b⃗(x)=2x2+x\vec{a}(x) \cdot \vec{b}(x) = 2x^2 + x. Evaluate the integral I=∫−12∣a⃗(x)×b⃗(x)∣ dxI = \int_{-1}^{2} |\vec{a}(x) \times \vec{b}(x)| \, dx

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