# Mathematics Delhi Set 2 2014-2015 CBSE (Commerce) Class 12 Question Paper Solution

Mathematics [Delhi Set 2]
Date: March 2015

[1]1

If a line makes angles 90°, 60° and θ with x, y and z-axis respectively, where θ is acute, then find θ.

Concept: Properties of Inverse Trigonometric Functions
Chapter: [1.01] Inverse Trigonometric Functions
[1]2

Write the element a23 of a 3 ✕ 3 matrix A = (aij) whose elements aij are given by a_(ij)=∣(i−j)/2∣

Concept: Introduction of Operations on Matrices
Chapter: [2.02] Matrices
[1]3

Find the differential equation representing the family of curves v=A/r+ B, where A and B are arbitrary constants.

Concept: Formation of a Differential Equation Whose General Solution is Given
Chapter: [3.04] Differential Equations
[1]4

Find the integrating factor of the differential equation.

((e^(-2^sqrtx))/sqrtx-y/sqrtx)dy/dx=1

Concept: Solutions of Linear Differential Equation
Chapter: [3.04] Differential Equations
[1]5

If vec a=7hati+hatj-4hatk and vecb=2hati+6hatj+3hatk , then find the projection of vec a and vecb

Concept: Product of Two Vectors - Scalar (Or Dot) Product of Two Vectors
Chapter: [4.02] Vectors
[1]6

Find λ, if the vectors veca=hati+3hatj+hatk,vecb=2hati−hatj−hatk and vecc=λhatj+3hatk  are coplanar.

Concept: Scalar Triple Product of Vectors
Chapter: [4.02] Vectors
[4]7 | Attempt any one
[4]7.1

A bag A contains 4 black and 6 red balls and bag B contains 7 black and 3 red balls. A die is thrown. If 1 or 2 appears on it, then bag A is chosen, otherwise bag B, If two balls are drawn at random (without replacement) from the selected bag, find the probability of one of them being red and another black.

Concept: Probability Examples and Solutions
Chapter: [6.01] Probability
[4]7.2

An unbiased coin is tossed 4 times. Find the mean and variance of the number of heads obtained.

Concept: Mean of a Random Variable
Chapter: [6.01] Probability
[4]8

If vecr=xhati+yhatj+zhatk ,find (vecrxxhati).(vecrxxhatj)+xy

Concept: Vectors Examples and Solutions
Chapter: [4.02] Vectors
[4]9

Find the distance between the point (−1, −5, −10) and the point of intersection of the line (x-2)/3=(y+1)/4=(z-2)/12 and the plane x-y+z=5

Concept: Three - Dimensional Geometry Examples and Solutions
Chapter: [4.01] Three - Dimensional Geometry
[4]10 | Attempt any one
[4]10.1

If sin [cot−1 (x+1)] = cos(tan1x), then find x.

Concept: Inverse Trigonometric Functions (Simplification and Examples)
Chapter: [1.01] Inverse Trigonometric Functions
[4]10.2

If (tan1x)2 + (cot−1x)2 = 5π2/8, then find x.

Concept: Inverse Trigonometric Functions (Simplification and Examples)
Chapter: [1.01] Inverse Trigonometric Functions
[4]11

If y=tan^(−1) ((sqrt(1+x^2)+sqrt(1−x^2))/(sqrt(1+x^2)−sqrt(1−x^2))) , x21, then find dy/dx.

Concept: Derivatives of Inverse Trigonometric Functions
Chapter: [3.01] Continuity and Differentiability
[4]12

If x = a cos θ + b sin θ, y = a sin θ − b cos θ, show that y^2 (d^2y)/(dx^2)-xdy/dx+y=0

Concept: Second Order Derivative
Chapter: [3.01] Continuity and Differentiability
[4]13

The side of an equilateral triangle is increasing at the rate of 2 cm/s. At what rate is its area increasing when the side of the triangle is 20 cm ?

Concept: Increasing and Decreasing Functions
Chapter: [3.02] Applications of Derivatives
[4]14

Find : int(x+3)sqrt(3-4x-x^2dx)

Concept: Methods of Integration - Integration by Substitution
Chapter: [3.05] Integrals
[4]15

Three schools A, B and C organized a mela for collecting funds for helping the rehabilitation of flood victims. They sold hand made fans, mats and plates from recycled material at a cost of Rs 25, Rs 100 and Rs 50 each. The number of articles sold are given below:

 SchoolArticle A B C Hand-fans 40 25 35 Mats 50 40 50 Plates 20 30 40

Find the funds collected by each school separately by selling the above articles. Also find the total funds collected for the purpose.

Write one value generated by the above situation.

Concept: Multiplication of Two Matrices
Chapter: [2.02] Matrices
[4]16 | Attempt any one
[4]16.1

If A=([2,0,1],[2,1,3],[1,-1,0]) find A2 - 5A + 4I and hence find a matrix X such that  A2 - 5A + 4I + X = 0

Concept: Operations on Matrices - Addition of Matrices
Chapter: [2.02] Matrices
[4]16.2

If A = [[1,-2,3],[0,-1,4],[-2,2,1]] ,find (A')-1

Concept: Inverse of a Matrix - Inverse of a Nonsingular Matrix by Elementary Transformation
Chapter: [2.02] Matrices
[4]17

If  f(x)=|[a,-1,0],[ax,a,-1],[ax^2,ax,a]|  , using properties of determinants find the value of f(2x) − f(x).

Concept: Properties of Determinants
Chapter: [2.01] Determinants
[4]18 | Attempt any one
[4]18.1

Find: I=intdx/(sinx+sin2x)

Concept: Methods of Integration - Integration Using Partial Fractions
Chapter: [3.05] Integrals
[4]18.2

Integrate the following w.r.t. x (x^3-3x+1)/sqrt(1-x^2)

Concept: Evaluation of Simple Integrals of the Following Types and Problems
Chapter: [3.05] Integrals
[4]19

Evaluate :

∫_(-pi)^pi (cos ax−sin bx)^2 dx

Concept: Evaluation of Definite Integrals by Substitution
Chapter: [3.05] Integrals
[6]20 | Attempt any one
[6]20.1

Solve the differential equation : (tan1yx)dy=(1+y2)dx.

Concept: General and Particular Solutions of a Differential Equation
Chapter: [3.04] Differential Equations
[6]20.2

Find the particular solution of the differential equation dy/dx=(xy)/(x^2+y^2) given that y = 1, when x = 0.

Concept: General and Particular Solutions of a Differential Equation
Chapter: [3.04] Differential Equations
[6]21

If lines (x−1)/2=(y+1)/3=(z−1)/4 and  (x−3)/1=(y−k)/2=z/1 intersect, then find the value of k and hence find the equation of the plane containing these lines.

Concept: Three - Dimensional Geometry Examples and Solutions
Chapter: [4.01] Three - Dimensional Geometry
[6]22

If A and B are two independent events such that P(barA∩ B) =2/15 and P(A ∩ barB) = 1/6, then find P(A) and P(B).

Concept: Independent Events
Chapter: [6.01] Probability
[6]23

Find the local maxima and local minima, of the function f(x) = sin x − cos x, 0 < x < 2π.

Concept: Maximum and Minimum Values of a Function in a Closed Interval
Chapter: [3.02] Applications of Derivatives
[6]24

Find graphically, the maximum value of z = 2x + 5y, subject to constraints given below :

2x + 4y  83

x + y  6

x + y  4

x  0, y 0

Concept: Graphical Method of Solving Linear Programming Problems
Chapter: [5.01] Linear Programming
[6]25

Let N denote the set of all natural numbers and R be the relation on N × N defined by (a, b) R (c, d) if ad (b + c) = bc (a + d). Show that R is an equivalence relation.

Concept: Types of Relations
Chapter: [1.02] Relations and Functions
[6]26 | Attempt any one
[6]26.1

Using integration find the area of the triangle formed by positive x-axis and tangent and normal of the circle

x^2+y^2=4 at (1, sqrt3)

Concept: Area Under Simple Curves
Chapter: [3.03] Applications of the Integrals
[6]26.2

Evaluate int_1^3(e^(2-3x)+x^2+1)dx  as a limit of sum.

Concept: Definite Integral as the Limit of a Sum
Chapter: [3.05] Integrals

#### Request Question Paper

If you dont find a question paper, kindly write to us

View All Requests

#### Submit Question Paper

Help us maintain new question papers on Shaalaa.com, so we can continue to help students

only jpg, png and pdf files

## CBSE previous year question papers Class 12 Mathematics with solutions 2014 - 2015

CBSE Class 12 Maths question paper solution is key to score more marks in final exams. Students who have used our past year paper solution have significantly improved in speed and boosted their confidence to solve any question in the examination. Our CBSE Class 12 Maths question paper 2015 serve as a catalyst to prepare for your Mathematics board examination.
Previous year Question paper for CBSE Class 12 Maths-2015 is solved by experts. Solved question papers gives you the chance to check yourself after your mock test.
By referring the question paper Solutions for Mathematics, you can scale your preparation level and work on your weak areas. It will also help the candidates in developing the time-management skills. Practice makes perfect, and there is no better way to practice than to attempt previous year question paper solutions of CBSE Class 12.

How CBSE Class 12 Question Paper solutions Help Students ?
• Question paper solutions for Mathematics will helps students to prepare for exam.
• Question paper with answer will boost students confidence in exam time and also give you an idea About the important questions and topics to be prepared for the board exam.
• For finding solution of question papers no need to refer so multiple sources like textbook or guides.