Maths
Maths
041
SAMPLE QUESTION PAPER
CLASS - XII (2025-26)
SECTION-A
This section comprises of multiple choice questions (MCQs) of 1 mark each.
Select the correct option (Question 1 - Question 18)
𝑥
(A) sin−1 𝑥 (B) sin−1(2𝑥) (C) sin−1 (2) (D) 2 sin−1 𝑥
5. 3 0 0 1
The inverse of the matrix [0 2 0] is…
0 0 5
1
0 0
0 0 3 3
1
(A) [0 2 0] (B) 0 2
0
5 0 0 1
[0 0 5]
1
−3 0 0
−3 0 0
1
(C) 0 −2 0 (D) [ 0 −2 0 ]
1 0 0 −5
[0 0 − 5]
10. The solution of the differential equation 𝑥𝑑𝑥 + 𝑦𝑑𝑦 = 0 represents a family of 1
(A) straight lines (B) parabolas (C) Circles (D) Ellipses
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11. 𝑏
If 𝑓(𝑎 + 𝑏 − 𝑥) = 𝑓(𝑥), then ∫𝑎 𝑥 𝑓(𝑥)𝑑𝑥 is equal to 1
𝑎+𝑏 𝑏 𝑎+𝑏 𝑏
(A) ∫𝑎 𝑓(𝑏 − 𝑥)𝑑𝑥 (B) ∫𝑎 𝑓(𝑎 − 𝑥)𝑑𝑥
2 2
𝑏−𝑎 𝑏 𝑎+𝑏 𝑏
(C) ∫𝑎 𝑓(𝑥) 𝑑𝑥 (D) ∫𝑎 𝑓(𝑥)𝑑𝑥
2 2
13. A bird flies through a distance in a straight line given by the vector 𝑖̂ + 2𝑗̂ + 𝑘̂ . A 1
man standing beside a straight metro rail track given by 𝑟⃗ = (3 + λ)𝑖̂ + (2λ −
1)𝑗̂ + 3λ𝑘̂ is observing the bird. The projected length of its flight on the metro
track is
6 14 8 5
(A) units (B) units (C) units (D) units
√14 √6 √14 √6
14. The distance of the point with position vector 3𝑖̂ + 4𝑗̂ + 5𝑘̂ from the y-axis is 1
(A) 4 units (B) √34 units (C) 5 units (D) 5√2 units
15. If 𝑎⃗ = 3𝑖̂ + 2𝑗̂ + 4𝑘̂ , 𝑏⃗⃗ = 𝑖̂ + 𝑗̂ − 3𝑘̂ and 𝑐⃗ = 6𝑖̂ − 𝑗̂ + 2𝑘̂ are three given vectors, 1
then (2𝑎⃗. 𝑖̂)𝑖̂ − (𝑏⃗⃗. 𝑗̂)𝑗̂ + (𝑐⃗. 𝑘̂)𝑘̂ is same as the vector
Maximise 𝑍 = 3𝑥 + 2𝑦 + 1
Subject to the constraints 𝑥 ≥ 0, 𝑦 ≥ 0, 3𝑥 + 4𝑦 ≤ 12,
He/ She notices the below shown graph for the said LPP problem, and finds that
a constraint is missing in it:
Help him/her choose the required constraint from the graph.
17. The feasible region of a linear programming problem is bounded but the 1
objective function attains its minimum value at more than one point. One of the
points is (5,0).
Then one of the other possible points at which the objective function attains its
minimum value is
18. A person observed the first 4 digits of your 6-digit PIN. What is the probability 1
that the person can guess your PIN?
1 1 1
(A) (B) (C) (D) 1
81 100 90
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ASSERTION-REASON BASED QUESTIONS
(A) Both (A) and (R) are true and (R) is the correct explanation of (A).
(B) Both (A) and (R) are true but (R) is not the correct explanation of (A).
(C) (A) is true but (R) is false.
(D) (A) is false but (R) is true.
19. √3
Assertion (A): Value of the expression sin−1 ( 2 ) + tan−1 1 − sec −1 (√2) is 4 .
𝜋 1
𝜋 𝜋
Reason (R): Principal value branch of sin−1 𝑥 is [− 2 , 2 ] and that of s𝑒𝑐 −1 𝑥
𝜋
is [0, 𝜋] − { 2 }.
20. Assertion(A): Given two non-zero vectors 𝑎⃗ and 𝑏⃗⃗ . If 𝑟⃗ is another non-zero 1
vector such that 𝑟⃗ × (𝑎⃗ + 𝑏⃗⃗) = ⃗⃗
0 . Then 𝑟⃗ is perpendicular to 𝑎⃗ × 𝑏⃗⃗ .
Reason (R): The vector (𝑎⃗ + 𝑏⃗⃗) is perpendicular to the plane of 𝑎⃗ and 𝑏⃗⃗
SECTION B
This section comprises of 5 very short answer (VSA) type questions of 2 marks each.
OR
22 𝜋 𝑥
If 𝑦 = log tan ( 4 + 2), then prove that
𝒅𝒚
− 𝐬𝐞𝐜 𝒙 = 𝟎 2
𝒅𝒙
23A (𝑥−3)
Find: ∫ (𝑥−1)3 𝑒 𝑥 𝑑𝑥 2
OR
23B Find out the area of shaded region in the enclosed figure.
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23 B For Visually Impaired:
Find out the area of the region enclosed by the curve 𝑦 2 = 𝑥 , 𝑥 = 3 and 𝑥-axis
in the first quadrant.
24. If 𝑓(𝑥 + 𝑦) = 𝑓(𝑥)𝑓(𝑦) for all 𝑥 , 𝑦 ∈ R and 𝑓(5)= 2, 𝑓 ′ (0) = 3, then using the 2
definition of derivatives, find 𝑓 ′ (5).
SECTION C
This section comprises of 6 short answer (SA) type questions of 3 marks each.
26A. 𝑑𝑦 log 𝑥
If 𝑥 𝑦 = 𝑒 𝑥−𝑦 prove that 𝑑𝑥 = (log(𝑥𝑒))2 and hence find its value at 𝑥 = 𝑒. 3
OR
𝑑2 𝑦
26B. If 𝑥 = 𝑎(𝜃 − sin 𝜃 ), 𝑦 = 𝑎 (1 − cos 𝜃 ) find .
𝑑𝑥 2
27 A spherical ball of ice melts in such a way that the rate at which its volume 3
decreases at any instant is directly proportional to its surface area. Prove that
the radius of the ice ball decreases at a constant rate.
2
28A Sketch the graph 𝑦 = |𝑥 + 1| . Evaluate ∫−4|𝑥 + 1|𝑑𝑥. What does the value of this 3
integral represent on the graph?
OR
28B Using integration find the area of the region {(𝑥, 𝑦) ∶ 𝑥 2 − 4𝑦 ≤ 0, 𝑦 − 𝑥 ≤ 0}
29A Find the distance of the point (2, −1,3) from the line 3
𝑟⃗ = (2𝑖̂ − 𝑗̂ + 2𝑘̂) + 𝜇(3𝑖̂ + 6𝑗̂ + 2𝑘̂ )
measured parallel to the z-axis.
OR
29B Find the point of intersection of the line 𝑟⃗ = (3𝑖̂ + 𝑘̂) + 𝜇(𝑖̂ + 𝑗̂ + 𝑘̂) and the line
through (2, −1,1) parallel to the z-axis. How far is this point from the z-axis?
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30. Solve graphically: 3
Maximise 𝑍 = 2𝑥 + 𝑦 subject to
𝑥 + 𝑦 ≤ 1200
𝑥 + 𝑦 ≥ 600
𝑥
𝑦≤ 2
𝑥 ≥ 0, 𝑦 ≥ 0 .
31. Two students Mehul and Rashi are seeking admission in a college. The 3
probability that Mehul is selected is 0.4 and the probability of selection of exactly
one of the them is 0.5. Chances of selection of them is independent of each
other. Find the chances of selection of Rashi. Also find the probability of selection
of at least one of them.
SECTION D
This section comprises of 4 long answer (LA) type questions of 5 marks each
32. 3 −6 −1 1 −2 −1 5
For two matrices 𝐴 = [ 2 −5 −1] and 𝐵 = [0 −1 −1], find the product 𝐴𝐵
−2 4 1 2 0 3
and hence solve the system of equations:
3𝑥 − 6𝑦 − 𝑧 = 3
2𝑥 − 5𝑦 − 𝑧 + 2 = 0
−2𝑥 + 4𝑦 + 𝑧 = 5
33A Evaluate:
1 log(1+𝑥)
∫0 𝑑𝑥 5
1+𝑥 2
OR
33B (3 sin 𝜃−2) cos 𝜃
Find ∫ 5−𝑐𝑜𝑠2 𝜃−4 sin 𝜃 𝑑𝜃
34A 𝑑
Solve the differential equation: 𝑦 + 𝑑𝑥 ( 𝑥𝑦 ) = 𝑥 (sin 𝑥 + 𝑥) 5
OR
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35. The two lines
𝑥−1
= −𝑦 , 𝑧 + 1 = 0 and
−𝑥
=
𝑦+1
= 𝑧 + 2 intersect at a point 5
3 2 2
whose y-coordinate is 1. Find the co-ordinates of their point of intersection. Find
the vector equation of a line perpendicular to both the given lines and passing
through this point of intersection.
SECTION- E
The department has collected the following data regarding one-way traffic flow
between spots:
The department wants to represent and analyze this data using relations and
functions. Use the given data to answer the following questions:
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37. Case Study -2 4
LED bulbs are energy-efficient because they use significantly less electricity than
traditional bulbs while producing the same amount of light. They convert more
energy into light rather than heat, reducing waste. Additionally, their long lifespan
means fewer replacements, saving resources and money over time.
𝐶(𝑥) = 0.5𝑥 2 − 10𝑥 + 150 and 𝑅(𝑥) = −0.3𝑥 2 + 20𝑥 respectively, where
𝐶(𝑥) and 𝑅(𝑥) are both in ₹.
To maximize the profit, the company needs to analyze these functions using
calculus. Use the given models to answer the following questions:
OR
III B. Identify the possible practical value of 𝑥 (i.e., the number of bulbs that can
realistically be produced and sold) that can maximize the profit, if the
resources available and the expenditure on machines allows to produce
minimum 10 but not more than 18 bulbs per hour. Also calculate the
maximum profit. [2]
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38. Case Study -3 4
Excessive use of screens can result in vision problems, obesity, sleep disorders,
anxiety, low retention problems and can impede social and emotional
comprehension and expression. It is essential to be mindful of the amount of
time we spend on screens and to reduce our screen-time by taking regular
breaks, setting time limits, and engaging in non-screen-based activities.
In a class of students of the age group 14 to 17, the students were categorised
into three groups according to a feedback form filled by them. The first group
constituted of the students who spent more than 4 hours per day on the mobile
screen or the gaming screens, while the second group spent 2 to 4 hours /day
on the same activities. The third group spent less than 2 hours /day on the same.
The first group with the high screen time is 60% of all the students, whereas the
second group with moderate screen time is 30% and the third group with low
screen time is only 10% of the total number of students. It was observed that
80% students of first group faced severe anxiety and low retention issues, with
70% of second group, and 30% of third group having the same symptoms.
I. What is the total percentage of students who suffer from anxiety and low
retention issues in the class? [2]
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MATHEMATICS – Code No. 041
MARKING SCHEME
CLASS – XII (2025-26)
AB is defined so n=4
AC is defined so p=4
2 AB and AC are square matrices of same order 1
so 𝑚 × 3 = 𝑚 × 𝑞 ⇒ 𝑞 = 3 = 𝑚
Answer is (A) 𝑚 = 𝑞 = 3 𝑎𝑛𝑑 𝑛 = 𝑝 = 4
As A is skew symmetric
So 𝑝 = 0, 𝑞 = 2, 𝑟 = −3, 𝑡 = 4
𝑞+𝑡 6
3 So 𝑝+𝑟 = −3 = −2 1
Answer is (A) -2
𝑓(𝑥) is continuous at 𝑥 = 𝜋
⇒ lim−(𝑘𝑥 + 1) = lim+ 𝑐𝑜𝑠 𝑥 = 𝑓(𝜋)
𝑥→𝜋 𝑥→𝜋
⇒ lim [𝑘(𝜋 − ℎ) + 1] = lim 𝑐𝑜𝑠( 𝜋 + ℎ ) = 𝑘𝜋 + 1
7 ℎ→0 ℎ→0 1
−2
⇒ 𝑘𝜋 + 1 = −1 ⇒𝑘 = 𝜋
−𝟐
Answer is (D) 𝝅
Page 1 of 12
𝑓(𝑥) = 𝑥 tan−1 𝑥
1
𝑓 ′ (𝑥) = 1. tan−1 𝑥 + 𝑥 . 1+𝑥 2
8 1 𝜋 1 1
𝑓 ′ (1) = 1 . tan−1 1 + 1+1 = +2
4
𝝅 𝟏
Answer is (B) 𝟒 + 𝟐
𝑓(𝑥) = 10 − 𝑥 − 2𝑥 2
⇒ 𝑓 ′ (𝑥) = −1 − 4𝑥
For increasing function 𝑓 ′ (𝑥) ≥ 0
⇒ − ( 1 + 4𝑥) ≥ 0
9 ⇒ ( 1 + 4𝑥) ≤ 0 1
⇒ 𝑥 ≤ − 1⁄4
1
⇒ 𝑥 ∈ (−∞, − 4]
𝟏
Answer is (A) (−∞, − ]
𝟒
𝑥𝑑𝑥 + 𝑦𝑑𝑦 = 0
⇒ ∫ 𝑥𝑑𝑥 = − ∫ 𝑦𝑑𝑦
𝑥2 𝑦2
⇒ =− +𝑘
2 2
10 2 2 1
⇒ 𝑥 + 𝑦 = 2𝑘
Solution is 𝑥 2 + 𝑦 2 = 2𝑘, 𝑘 being an arbitrary constant.
Answer is (C) Circles
𝑏 𝑏
𝐼 = ∫𝑎 𝑥 𝑓(𝑥)𝑑𝑥 = ∫𝑎 (𝑎 + 𝑏 − 𝑥)𝑓(𝑎 + 𝑏 − 𝑥)𝑑𝑥
𝑏
⇒ 𝐼 = ∫𝑎 (𝑎 + 𝑏 − 𝑥)𝑓(𝑥)𝑑𝑥 (given 𝑓(𝑎 + 𝑏 − 𝑥) = 𝑓(𝑥) )
𝑏 𝑏
⇒ 𝐼 = ∫𝑎 (𝑎 + 𝑏) 𝑓(𝑥)𝑑𝑥 − ∫𝑎 𝑥 𝑓(𝑥)𝑑𝑥
11 𝑏
⇒ 2 𝐼 = (𝑎 + 𝑏) ∫𝑎 𝑓(𝑥)𝑑𝑥 1
1 𝑏
⇒ 𝐼 = 2 (𝑎 + 𝑏) ∫𝑎 𝑓(𝑥)𝑑𝑥
𝒂+𝒃 𝒃
Answer is (D) 𝟐 ∫𝒂 𝒇(𝒙)𝒅𝒙
Page 2 of 12
The distance of the point (a, b, c) from the y-axis is √𝑎2 + 𝑐 2
14 So, the distance is √32 + 52 = √34 units. 1
Answer is (B) √𝟑𝟒 units
17 Answer is (C) Open Half plane that contains origin, but not the points of the
line 3𝑥 + 5𝑦 = 10 1
(V.I.)
𝟏
Answer is (B) 𝟏𝟎𝟎
The person knows the first 4 digits. So the person has to guess the remaining
18 two digits. 1
1 1 1
P (guessing the PIN )=1×1×1×1×10 × 10 = 100
√3 𝜋 𝜋 𝜋 𝜋 𝜋
sin−1 ( 2 ) + tan−1 1 − sec −1(√2) = 3 + 4 − 4 = ≠
3 4
So, A is false.
𝜋 𝜋 𝜋
19 Principal Value branch of sin−1 𝑥 is [− 2 , 2 ] and that of s𝑒𝑐 −1 𝑥 is [0, 𝜋] − {2 }. 1
So, R is true
Answer is (D)Assertion is false, but Reason is true
C. 𝑟⃗ × (𝑎⃗ + 𝑏⃗⃗) = ⃗0⃗ ⇒ 𝑟⃗ is parallel to (𝑎⃗ + 𝑏⃗⃗) and (𝑎⃗ + 𝑏⃗⃗) lies on the plane
of 𝑎⃗ and 𝑏⃗⃗ .
So, 𝑟⃗ is parallel to the plane of 𝑎⃗ and 𝑏⃗⃗ ⇒ 𝑟⃗ is perpendicular to (𝑎⃗ × 𝑏⃗⃗).
20 So, Assertion is true 1
But (𝑎⃗ + 𝑏⃗⃗) lies on the plane of 𝑎⃗ and 𝑏⃗⃗, so (𝑎⃗ + 𝑏⃗⃗) is not perpendicular to
the plane of 𝑎⃗ 𝑎𝑛𝑑 𝑏⃗⃗
Therefore, Reason is false.
Answer is (C) Assertion is true, but Reason is false
Page 3 of 12
SECTION B
(VSA type questions of 2 marks each)
21A 𝜋
tan (tan−1(−1) + 3 ) = tan (− 4 + 3 )
𝜋 𝜋 ½
𝜋 𝜋
tan −tan
= 3
𝜋
4
𝜋 1
1+tan tan
3 4
√3−1
= 1+√3 𝑜𝑟 2 − √3 ½
OR OR
22 𝑦 = log tan ( 4 + 2)
𝜋 𝑥
1 2 1 𝑑 1
= ∫ ( (𝑥−1)2 − (𝑥−1)3 ) 𝑒 𝑥 𝑑𝑥 = ∫ ((𝑥−1)2 + 𝑑𝑥 ((𝑥−1)2 )) 𝑒 𝑥 𝑑𝑥 1
𝑒𝑥
= (𝑥−1)2
+c (as ∫(𝑓(𝑥) + 𝑓 ′ (𝑥))𝑒 𝑥 𝑑𝑥 = 𝑒 𝑥 𝑓(𝑥) + c) 1
OR OR
4 4
23B A = ∫0 𝑥 𝑑𝑦 = ∫0 √𝑦 𝑑𝑦
2 3⁄ 𝑦=4 16 1
=3×𝑦 2]
𝑦=0
= 3 sq. units
1
23B For Visually Impaired:
3 3
A = ∫0 𝑦 𝑑𝑥 = ∫0 √𝑥 𝑑𝑥 1
2 3⁄ 𝑥=3 1
=3×𝑥 2]
𝑥=0
= 2√3 sq. units
Page 4 of 12
24 Given 𝑓(𝑥 + 𝑦) = 𝑓(𝑥)𝑓(𝑦)
𝑓(0 + 5) = 𝑓(0)𝑓(5)
⟹ 𝑓(0) = 1 ½
′ (5) 𝑓 (5+ℎ)−𝑓(5) 𝑓 (5)𝑓(ℎ)−𝑓(5)
𝑓 = lim = lim [ ∵ 𝑓(𝑥 + 𝑦) = 𝑓(𝑥)𝑓(𝑦 ) ]
ℎ→0 ℎ ℎ→0 ℎ
2𝑓(ℎ)−2
= lim [ ∵ 𝑓(5) = 2] 1
ℎ→0 ℎ
𝑓(ℎ)−1 𝑓(ℎ)−𝑓(0)
= 2 lim = 2 lim = 2 𝑓 ′ (0)
ℎ→0 ℎ ℎ→0 ℎ
= 2 (3) [∵ 𝑓 ′ (0) = 3] ½
=6
25 1
𝑂𝑃 = 2 (4𝑖̂ + 4𝑘̂) = 2𝑖̂ + 2𝑘̂
The vector ⃗⃗⃗⃗⃗⃗ ½
Area of the parallelogram formed by the two adjacent sides as OA and OP
𝑖̂ 𝑗̂ 𝑘̂ ½
⃗⃗⃗⃗⃗⃗ ⃗⃗⃗⃗⃗⃗
= |(𝑂𝐴 X 𝑂𝑃) | = ||1 1 1||
2 0 2
= |2𝑖̂ − 2𝑘̂ | ½
= 2√2 square units. ½
SECTION C
(SA type questions of 3 marks each)
26A 𝑥 𝑦 = 𝑒 𝑥−𝑦
Taking log of both sides
𝑦 log 𝑥 = (𝑥 − 𝑦) log 𝑒
𝑦 log 𝑥 + y = 𝑥 ( since log 𝑒 = 1)
𝑥
⟹ 𝑦 = 1+log 𝑥 1
Differentiating with respect to 𝑥
1
𝑑𝑦 (1+log 𝑥) .1− 𝑥 .
𝑥
= (1+log 𝑥)2
𝑑𝑥
log 𝑥
= (log 𝑒+log 𝑥)2
log 𝑥 1
= (log(𝑥 𝑒))2
𝑑𝑦 log 𝑒 1 1 1
Now ] = = (2𝑙𝑜𝑔𝑒)2 = 22 = (as log 𝑒 = 1) 1
𝑑𝑥 𝑥=𝑒 (log 𝑒 2 )2 4
Alternative Solution:
𝑥 𝑦 = 𝑒 𝑥−𝑦
Taking log of both sides
𝑦 log 𝑥 = (𝑥 − 𝑦) log 𝑒
𝑦 log 𝑥 + y = 𝑥 ( since log 𝑒 = 1)
Differentiating both sides w.r.t. x
𝑑𝑦 𝑦 𝑑𝑦
log 𝑥 𝑑𝑥 + 𝑥 + 𝑑𝑥 = 1
𝑑𝑦 𝑦
⇒ 𝑑𝑥 (1 + log 𝑥) = 1 − 𝑥
𝑥
𝑑𝑦 𝑥−𝑦 𝑥− 𝑥(1+log 𝑥)−𝑥 𝑥(1+log 𝑥−1) log 𝑥
1+log 𝑥
⇒ 𝑑𝑥 = 𝑥(1+log 𝑥) = 𝑥(1+log 𝑥) = = 𝑥(log 𝑒+log 𝑥)2 = (log(𝑥𝑒))2
𝑥(1+log 𝑥)2
𝑑𝑦 log 𝑒 1 1 1
Now ] = (log 𝑒 2 )2 = (2𝑙𝑜𝑔𝑒)2
= 22 = 4 (as log 𝑒 = 1)
𝑑𝑥 𝑥=𝑒
Page 5 of 12
OR OR
𝑑𝑥 𝑑𝑦
26B = 𝑎(1 − cos 𝜃 ) , 𝑑𝜃 = 𝑎(0 + sin 𝜃), 1
𝑑𝜃
𝑑𝑦
𝑑𝑦 𝑎 sin 𝜃
⇒ 𝑑𝑥 = 𝑑𝜃
𝑑𝑥 = 𝑎(1−cos 𝜃 )
𝑑𝜃
𝜃
2 sin( ) cos( )
𝜃 1
𝜃
= 2
𝜃
2
= cot 2
2𝑠𝑖𝑛2 ( )
2
𝑑2 𝑦 1 𝜃 𝑑𝜃
⇒ 𝑑𝑥 2 = − 2 𝑐𝑜𝑠𝑒𝑐 2 ( 2) 𝑑𝑥
1 𝜃 1
= − 2𝑎 𝑐𝑜𝑠𝑒𝑐 2 ( 2) 𝜃
2𝑠𝑖𝑛2 ( )
2
1 𝜃 1
= − 4𝑎 𝑐𝑜𝑠𝑒𝑐 4 ( 2)
28A
2 −1 2
∫−4|𝑥 + 1|𝑑𝑥= ∫−4 (−𝑥 − 1) 𝑑𝑥 + ∫−1(𝑥 + 1) 𝑑𝑥 ½
(𝑥+1)2 −1 (𝑥+1)2 2
= − ] + ] ½
2 −4 2 −1
9 9
= − (0 − 2) + (2 − 0) = 9 ½
It represent the area of shaded region bounded by the curve 𝑦 = |𝑥 + 1|, ½
𝑥 − axis and the lines 𝑥 = −4 𝑎𝑛𝑑 𝑥 = 2
Page 6 of 12
OR
28B
4 4 𝑥2
Required Area = ∫0 𝑥 𝑑𝑥 − ∫0 𝑑𝑥 1
4
4
𝑥2 1 ½
= ] − 12 [𝑥 3 ]40
2 0
1 1 16 8 ½
= 2 (16 − 0) − 12 (64 − 0) = 8 − = 3 sq. units
3
−𝑥 − 1, 𝑥 < −1
𝑦 = |𝑥 + 1| = 𝑓(𝑥) = {
𝑥 + 1, 𝑥 ≥ −1 1
2 −1 2
∫−4|𝑥 + 1|𝑑𝑥= ∫−4 (−𝑥 − 1) 𝑑𝑥 + ∫−1(𝑥 + 1) 𝑑𝑥
(𝑥+1)2 −1 (𝑥+1)2 2
= − ] + ] 1
2 −4 2 −1
9 9
= − (0 − ) + ( − 0) = 9
2 2
It represent the area of shaded region bounded by the curve 𝑦 = |𝑥 + 1|, 1
𝑥 − axis and the lines 𝑥 = −4 𝑎𝑛𝑑 𝑥 = 2
OR
Page 7 of 12
𝑥2 𝑦2 𝑥2 𝑦2 5
25𝑥 2 + 16𝑦 2 = 400 ⇒ 16 + 25 = 1 ⇒ 42 + 52 = 1 ⇒ 𝑦 = 4 √42 − 𝑥 2
45
Required Area = 4 ∫0 4 √42 − 𝑥 2 𝑑𝑥 1
4
𝑥√42 −𝑥 2 42 𝑥
= 5[ + sin−1 (4)] 1
2 2
0
−1 (1)
= 5[0 + 8 sin − 0]
𝜋
= 40 × 2 = 20𝜋 sq. units 1
29A The line through (2, −1,3) parallel to the z-axis is given by
𝑟⃗ = (2𝑖̂ − 𝑗̂ + 3𝑘̂ ) + λ(𝑘̂) 1
Any point on this line is P (2, −1, 3 + 𝜆 ) ½
Any point on the given line 𝑟⃗ = (2𝑖̂ − 𝑗̂ + 2𝑘̂) + 𝜇(3𝑖̂ + 6𝑗̂ + 2𝑘̂) is
Q (2 + 3𝜇, −1 + 6𝜇, 2 + 2𝜇)
½
For the intersection point
½
Q (2 + 3𝜇, −1 + 6𝜇, 2 + 2𝜇) = P (2, -1, 3+ λ ) ⇒ 2 = 2 + 3 𝜇 ⇒ 𝜇 = 0
½
The point of intersection is (2, −1,2)
The distance from (2, −1,3) to (2, −1,2) is clearly 1 unit.
Alternative Solution:
Any point on the line through (2, −1, 3) parallel to the z-axis is (2, −1, 𝜆)
Any point on the given line is (2 + 3𝜇, −1 + 6𝜇, 2 + 2𝜇) 1
Therefore, 2 = 2 + 3 𝜇 ⇒ 𝜇 = 0 1
The point of intersection is (2, −1,2) ½
The distance from (2, −1,3) to (2, −1,2) is clearly 1 unit. ½
OR
29B
The line through (2,−1,1)parallel to the z-axis is 𝑟⃗ = (2𝑖̂ − 𝑗̂ + 𝑘̂ ) + λ(𝑘̂) 1
Any point on this line is P (2, −1, 1+ λ )
Any point on the given line is A (3+ 𝜇, 𝜇, 1+ 𝜇 )
A (3+ 𝜇, 𝜇, 1+ 𝜇 ) = P (2, −1, 1+ λ ) ⇒ 𝜇 = −1 1
The point of intersection is (2, −1,0) ½
The distance of (2, −1, 0) from the z-axis is √22 + (−1)2 = √5 units. ½
30 Sketching the graph 1
1
2
Page 8 of 12
Corner points A(600,0), B(1200,0), C(800,400), D(400,200)
Values of Z: 𝑍𝐴 = 1200, 𝑍𝐵 = 2400, 𝑍𝐶 = 2000, 𝑍𝐷 = 1000 ½
Maximum 𝑍 = 2400 when 𝑥 = 1200 and 𝑦 = 0 ½
½
For Visually Impaired:
At Corner points A(600,0), B(1200,0), C(800,400), D(400,200)
30 Values of Z are 𝑍𝐴 = 1800, 𝑍𝐵 = 3600, 𝑍𝐶 = 3200, 𝑍𝐷 = 1600 1
Maximum Value of Z = 3600 at B(1200,0) 1
And Minimum Value of Z= 1600 at D(400,200) 1
𝜋 1
4
= log 2 × 𝑥]0 − 𝐼
𝜋 1
⇒ 2𝐼 = log 2
4
𝜋
⇒ 𝐼= log 2
8 ½
33B OR OR
34A 𝑑
𝑦 + 𝑑𝑥 ( 𝑥𝑦 ) = 𝑥 (sin 𝑥 + 𝑥)
𝑑𝑦
⟹ 𝑦 + (𝑥 𝑑𝑥 + 𝑦 ) = 𝑥 (sin 𝑥 + 𝑥)
𝑑𝑦
1
⟹ 2𝑦 + 𝑥 𝑑𝑥 = 𝑥 (sin 𝑥 + 𝑥)
𝑑𝑦 2𝑦
⟹ 𝑑𝑥 + = (sin 𝑥 + 𝑥)
𝑥
𝑑𝑦
This a linear differential equation of the form 𝑑𝑥 + 𝑃𝑦 = 𝑄
2
P= ,Q=(sin 𝑥 + 𝑥)
𝑥
2
1
∫ 𝑥 dx 2 𝑙𝑜𝑔 𝑥 𝑙𝑜𝑔 𝑥 2 2
I.F =𝑒 = 𝑒 =𝑒 =𝑥
Solution will be 𝑦 . I.F =∫ 𝑄. 𝐼𝐹 𝑑𝑥 1
𝑦𝑥 2 = ∫(𝑠𝑖𝑛 𝑥 + 𝑥) 𝑥 2 dx
𝑦𝑥 2 =∫ 𝑠𝑖𝑛𝑥. 𝑥 2 𝑑𝑥 + ∫ 𝑥 3 𝑑𝑥
Page 10 of 12
𝑥4 1
⟹ 𝑦𝑥 2 = −𝑥 2 cos 𝑥 + 2 ∫ 𝑥 cos 𝑥 𝑑𝑥 + +C
4
𝑥4
⟹ 𝑦𝑥 2 = −𝑥 2 𝑐𝑜𝑠 𝑥 +2 (𝑥 𝑠𝑖𝑛𝑥 + 𝑐𝑜𝑠 𝑥) + 4 + C
Which is the required solution 1
OR
𝑥⁄ 𝑥⁄
2𝑦 𝑒 𝑦 𝑑𝑥 + ( 𝑦 − 2𝑥 𝑒 𝑦 ) 𝑑𝑦 = 0
34B 𝑥 𝑥 𝑦
𝑥
𝑑𝑥 2𝑥 𝑒 ⁄𝑦 −𝑦 2 𝑒 −1
𝑦
⟹ = 𝑥 = 𝑥
𝑑𝑦 2𝑦 𝑒 ⁄𝑦 2 𝑒𝑦 1
It is a homogeneous differential equation.
𝑑𝑥 𝑑𝑣
Let 𝑥 = 𝑣𝑦 ⟹ 𝑑𝑦 = 𝑣 +𝑦 𝑑𝑦 1
𝑑𝑣 2𝑣𝑒 𝑣 −1
𝑣 +𝑦 𝑑𝑦 = 2𝑒 𝑣
𝑑𝑣 2𝑣𝑒 𝑣 −1 2𝑣𝑒 𝑣 −1−2𝑣𝑒 𝑣
⟹ 𝑦 𝑑𝑦 = –𝑣=
2𝑒 𝑣 2𝑒 𝑣
𝑑𝑣 −1
⟹ 𝑦 =
𝑑𝑦 2𝑒 𝑣
𝑣 𝑑𝑦
⟹ 2𝑒 𝑑𝑣 = − 𝑦 1
𝑣 𝑑𝑦
∫ 2𝑒 𝑑𝑣 = − ∫ 𝑦
𝑣
⟹ 2𝑒 = − log |𝑦| + C
𝑥
⟹ 2𝑒 𝑦 +" 𝑙𝑜𝑔|𝑦| = C 1
When 𝑥 = 0 , 𝑦 = 1 , C = 2
𝑥
Required solution 2 𝑒 𝑦 + log|𝑦| = 2
1
35 Let
𝑥−1
=
𝑦−0
=
𝑧+1
=𝜆 ⇒ Any point on it is (3 𝜆 +1, − 𝜆, −1) ½
3 −1 0
1
For the point where 𝑦 = 1 ⇒ 𝜆 = −1
½
⇒ The point is (−2, 1 , −1)
1
The directions of the two lines are 𝑚 ⃗⃗⃗ = 3𝑖̂ − 𝑗̂
½
and 𝑛⃗⃗ = −2𝑖̂ + 2𝑗̂ + 𝑘̂
𝑖̂ 𝑗̂ 𝑘̂
⃗⃗⃗ × 𝑛⃗⃗ = | 3 −1 0| = −𝑖̂ − 3𝑗̂ + 4𝑘̂
𝑚 1
−2 2 1
The equation of the required line is
𝑟⃗ = (−2𝑖̂ + 𝑗̂ − 𝑘̂) + 𝜇(−𝑖̂ − 3𝑗̂ + 4𝑘̂) ½
Alternative Solution:
𝑥−1 𝑦−0 𝑧+1
Let = = = 𝜆 ⇒ Any point on it is (3 𝜆 + 1, − 𝜆, −1) ½
3 −1 0
For the point where 𝑦 = 1 ⇒ 𝜆 = −1 1
⇒ The point is (−2, 1, −1) ½
Let the direction ratios of the required line be a, b, c
Then 3𝑎 − 𝑏 = 0
And −2𝑎 + 2𝑏 + 𝑐 = 0 1
𝑎 −𝑏 𝑐 𝑎 𝑏 𝑐 1
Solving we get = = 4 ⇒ −1 = −3 = 4
−1 3
𝑥+2 𝑦−1 𝑧+1
The required line is = = =𝜇 ½
−1 −3 4
In vector form 𝑟⃗ = (−2𝑖̂ + 𝑗̂ − 𝑘̂) + 𝜇(−𝑖̂ − 3𝑗̂ + 4𝑘̂) ½
Page 11 of 12
SECTION- E
(3 case-study/passage-based questions of 4 marks each)
36 I. Traffic flow is not reflexive as (𝐴, 𝐴) ∉ 𝑅 (or no major spot is connected
with itself) 1
II. Traffic flow is not transitive as (𝐴, 𝐵) ∈ 𝑅 𝑎𝑛𝑑 (𝐵, 𝐸) ∈ 𝑅, 𝑏𝑢𝑡 (𝐴, 𝐸) ∉ 𝑅 1
III A. 𝑅 = {(𝐴, 𝐵), (𝐴, 𝐶), (𝐴, 𝐷), (𝐵, 𝐶), (𝐵, 𝐸), (𝐶, 𝐸), (𝐷, 𝐸), (𝐷, 𝐶)} 1
Domain = {𝐴, 𝐵, 𝐶, 𝐷} ½+
Range = {𝐵, 𝐶, 𝐷, 𝐸} ½
OR
III B. No, the traffic flow doesn’t represent a function as A has three images. 1+1
OR
III B. As 𝑥 is the number of bulbs, so practically 18 bulbs correspond to a
maximum profit. 1
Maximum profit is 𝑃(18) = −0.8 × 182 + 30 × 18 − 150
= −259.2 + 540 − 150 1
= 540 − 409.2 = ₹130.80
38 Let the events be
E1: the student is in the first group (time spent on screen is more than 4 hours)
E2: the student is in the second group (time spent on screen is 2 to 4 hours)
E3: the student is in third group (time spent on screen is less than 2 hours)
A: the event of the student showing symptoms of anxiety and low retention
60 30 10
P(E1) = 100 P(E2) = 100 and P(E3) = 100
80 70 30
P(A|E1) = 100 P(A|E2) = 100 and P(A|E3) = 100
𝑃(𝐸1 ∩𝐴)
II. P(E1|A) = 𝑃(𝐴)
60 80
( x
100 100
) 48 2 2
= 72 = 72 = 3
( )
100
Page 12 of 12