The first 5 questions are solved below. Log in as a Grade 12 student to reveal solutions for the rest of this paper.
Log In →
Q1
mcq
1 mark
The given graph illustrates:
-
A.
y = tan⁻¹x
-
B.
y = cosec⁻¹x
-
C.
y = cot⁻¹x
-
D.
y = sec⁻¹x
Correct Answer: C —
Solution
The graph of y = cot⁻¹x is a strictly decreasing function with a range of (0, π) and domain R. It passes through (0, π/2). Options (a), (b), and (d) do not represent this specific shape.
Q2
mcq
1 mark
Domain of f(x) = cos⁻¹x + sin x is:
-
A.
R
-
B.
(–1, 1)
-
C.
[–1, 1]
Correct Answer: C —
Solution
The domain of cos⁻¹x is [–1, 1] and the domain of sin x is R. The intersection of [–1, 1] and R is [–1, 1].
Q3
mcq
1 mark
What is the total number of possible matrices of order 3 × 3 with each entry as 2 or 3?
Correct Answer: B —
Solution
A 3x3 matrix has 9 entries. Each entry can be chosen in 2 ways. Total number of matrices = 2^9 = 512.
Q4
mcq
1 mark
The matrix A = [[3,0,0],[0,2,0],[0,0,5]] is a/an:
-
A.
scalar matrix
-
B.
identity matrix
-
C.
null matrix
-
D.
symmetric matrix
Correct Answer: D —
Solution
A symmetric matrix is one where A = Aᵀ. Since the given matrix is diagonal, it satisfies this property. It is not scalar (elements are not equal) or identity (diagonal elements are not 1).
Q5
mcq
1 mark
If A and B are two square matrices each of order 3 with |A| = 3 and |B| = 5 then |2AB| is:
-
A.
30
-
B.
120
-
C.
15
-
D.
225
Correct Answer: B —
Solution
|2AB| = 2^3 |A| |B| = 8 * 3 * 5 = 120. Using property |kA| = k^n|A| for order n=3.
Q6
mcq
1 mark
Let A be a square matrix of order 3. If |A| = 5, then |adj A| is:
Q7
mcq
1 mark
If [[2x²+1, 3x],[x–3, 12]] = [[0, y–1],[0, 35]], then the value of (x – y) is:
-
A.
2 or 10
-
B.
–2 or 10
-
C.
2 or –10
-
D.
–2 or –10
Q8
mcq
1 mark
If f(x) = { 1, if x ≤ 3; ax + b, if 3 < x < 5; 7, if x ≥ 5 } is continuous in R, then the values of a and b are:
-
A.
a = 3, b = –8
-
B.
a = 3, b = 8
-
C.
a = –3, b = –8
-
D.
a = –3, b = 8
Q9
mcq
1 mark
If f(x) = –2x⁸, then the correct statement is:
-
A.
f(1/2) = f(–1/2)
-
B.
f(1/2) = –f(–1/2)
-
C.
f(–1/2) = –f(1/2)
-
D.
f(1/2) = –(–f(1/2))
Q10
mcq
1 mark
A spherical ball has a variable diameter (5/2)(3x + 1). The rate of change of its volume w.r.t. x, when x = 1, is:
-
A.
225
-
B.
300
-
C.
375
-
D.
125
Q11
mcq
1 mark
If f: R → R is defined as f(x) = 2x – sin x, then f is:
-
A.
a decreasing function
-
B.
an increasing function
-
C.
maximum at x = π/2
-
D.
maximum at x = 0
Q12
mcq
1 mark
∫ (e^(9log x) – e^(8log x)) / (e^(6log x) – e^(5log x)) dx is equal to:
-
A.
x + C
-
B.
x²/2 + C
-
C.
x⁴/4 + C
-
D.
x³/3 + C
Q13
mcq
1 mark
For a function f(x), which of the following holds true?
-
A.
∫[a to b] f(x)dx = ∫[a to b] f(a+b–x)dx
-
B.
∫[–a to a] f(x)dx = 0, if f is an even function
-
C.
∫[–a to a] f(x)dx = 2∫[0 to a] f(x)dx, if f is an odd function
-
D.
∫[0 to 2a] f(x)dx = 2∫[0 to a] f(x)dx – ∫[0 to a] f(2a–x)dx
Q14
mcq
1 mark
∫ eˣ / (4 – e^(2x)) dx is equal to:
-
A.
(1/2)cos⁻¹(eˣ) + C
-
B.
(1/2)sin⁻¹(eˣ) + C
-
C.
eˣ/2 + C
-
D.
sin⁻¹(eˣ/2) + C
Q15
mcq
1 mark
A student tries to tie ropes, parallel to each other from one end of the wall to the other. If one rope is along the vector 3î + 15ĵ + 6k̂ and the other is along the vector 2î + 10ĵ + λk̂, then the value of λ is:
Q16
mcq
1 mark
If |a⃗ + b⃗| = |a⃗ – b⃗| for any two vectors, then vectors a⃗ and b⃗ are:
-
A.
orthogonal vectors
-
B.
parallel to each other
-
C.
unit vectors
-
D.
collinear vectors
Q17
mcq
1 mark
If P(A) = 1/7, P(B) = 5/7 and P(A ∪ B) = 4/7, then P(A|B) is:
-
A.
6/7
-
B.
3/4
-
C.
4/5
-
D.
1/5
Q18
mcq
1 mark
A coin is tossed and a card is selected at random from a well shuffled pack of 52 playing cards. The probability of getting head on the coin and a face card from the pack is:
-
A.
2/13
-
B.
3/26
-
C.
19/26
-
D.
3/13
Q19
mcq
1 mark
Assertion: f(x) = { x·sin(1/x), x ≠ 0; 0, x = 0 } is continuous at x = 0.
Reason: When x → 0, sin(1/x) is a finite value between –1 and 1.
-
A.
Both Assertion and Reason are true and Reason is the correct explanation of the Assertion.
-
B.
Both Assertion and Reason are true, but Reason is not the correct explanation of the Assertion.
-
C.
Assertion is true, but Reason is false.
-
D.
Assertion is false and Reason is also false.
Q20
mcq
1 mark
Assertion: Set of values of sec⁻¹(3/2) is a null set.
Reason: sec⁻¹x is defined for x ∈ R – (–1, 1).
-
A.
Both Assertion and Reason are true and Reason is the correct explanation of the Assertion.
-
B.
Both Assertion and Reason are true, but Reason is not the correct explanation of the Assertion.
-
C.
Assertion is true, but Reason is false.
-
D.
Assertion is false and Reason is also false.
Q21
short answer
2 marks
Let f: A → B be defined by f(x) = (x – 2)/(x – 3), where A = R – {3} and B = R – {1}. Discuss the bijectivity of the function.
Q22
short answer
2 marks
If A = [[2, 3],[1, –2]], then show that A² – 4A + 7I = 0.
Q23
short answer
2 marks
(a) Differentiate (5^x)/(x^5) with respect to x.
OR
(b) If –2x² – 5x + y³ = 78, then find dy/dx.
Q24
short answer
2 marks
In a Linear Programming Problem, the objective function Z = 5x + 4y needs to be maximised under constraints 3x + y ≤ 6, x ≥ 1, x, y ≥ 0. Express the LPP on the graph and shade the feasible region and mark the corner points.
Q25
short answer
2 marks
(a) 10 identical blocks are marked with '0' on two of them, '1' on three of them, '2' on four of them and '3' on one of them and put in a box. If X denotes the number written on the block, then write the probability distribution of X and calculate its mean.
OR
(b) In a village of 8000 people, 3000 go out of the village to work and 4000 are women. It is noted that 30% of women go out of the village to work. What is the probability that a randomly chosen individual is either a woman or a person working outside the village?
Q26
long answer
3 marks
(a) Show that the function f: R → R defined by f(x) = 4x³ – 5, ∀ x ∈ R is one-one and onto.
OR
(b) Let R be a relation defined...
Q26
short answer
3 marks
(a) Show that the function f: R → R defined by f(x) = 4x³ – 5, ∀ x ∈ R is one-one and onto.
OR
(b) Let R be a relation defined on a set N of natural numbers such that R = {(x, y) : xy is a square of a natural number, x, y ∈ N}. Determine if the relation R is an equivalence relation.
Q27
short answer
3 marks
(a) Let 2x + 5y – 1 = 0 and 3x + 2y – 7 = 0 represent the equations of two lines on which the ants are moving on the ground. Using matrix method, find a point common to the paths of the ants.
OR
(b) A shopkeeper sells 50 Chemistry, 60 Physics and 35 Maths books on day I and sells 40 Chemistry, 45 Physics and 50 Maths books on day II. If the selling price for each such subject book is ₹150 (Chemistry), ₹175 (Physics) and ₹180 (Maths), then find his total sale in two days, using matrix method. If cost price of all the books together is ₹35,000, what profit did he earn after the sale of two days?
Q28
short answer
3 marks
Differentiate y = log(sin(x³/3 – 1)) with respect to x.
Q29
short answer
3 marks
Amongst all pairs of positive integers with product as 289, find which of the two numbers add up to the least.
Q30
short answer
3 marks
In the Linear Programming Problem for objective function Z = 18x + 10y subject to constraints 4x + y ≤ 20, 2x + 3y ≤ 30, x, y ≥ 0, find the minimum value of Z.
Q31
short answer
3 marks
(a) The scalar product of the vector a = î – ĵ + 2k̂ with a unit vector along the sum of vectors b = 2î – 4ĵ + 5k̂ and c = λî + 2ĵ – 3k̂ is equal to 1. Find the value of λ.
OR
(b) Find the shortest distance between the lines:
r = (2î – ĵ + 3k̂) + λ(î – 2ĵ + 3k̂)
r = (î + 4k̂) + μ(3î – 6ĵ + 9k̂).
Q32
long answer
5 marks
(a) Find: ∫ (x + 1) / ((x + 2)(2x + 1)) dx
OR
(b) Evaluate: ∫₀^π (x tan x) / (sec x + tan x) dx
Q33
long answer
5 marks
A woman discovered a scratch along a straight line on a circular table top of radius 8 cm. She divided the table top into 4 equal quadrants and discovered the scratch passing through the origin inclined at an angle π/4 anticlockwise along the positive direction of x-axis. Find the area of the region enclosed by the x-axis, the scratch and the circular table top in the first quadrant, using integration.
Q34
long answer
4 marks
Solve the differential equation dy/dx = cos x – 2y.
Q35
long answer
5 marks
(a) Find the point Q on the line (2x + 4)/6 = (y + 1)/2 = (2z + 6)/(–4) at a distance of 3√2 from the point P(1, 2, 3).
OR
(b) Find the image of the point (–1, 5, 2) in the line (2x – 4)/2 = (y – 2)/2 = z/3. Find the length of the line segment joining the points (given point and the image point).
Q36
long answer
4 marks
Three friends A, B and C move out from the same location O at the same time in three different directions to reach their destinations. They move out on straight paths and decide that A and B after reaching their destinations will meet up with C at his predecided destination, following straight paths from A to C and B to C in such a way that OA = a, OB = b and OC = 5a – 2b respectively.
Based upon the above information, answer the following questions:
(i) Complete the given figure to explain their entire movement plan along the respective vectors.
(ii) Find vectors AC and BC.
(iii) (a) If a·b = 1, distance of O to A is 1 km and that from O to B is 2 km, then find the angle between OA and OB. Also, find |a × b|.
OR
(iii) (b) If a = 2î – ĵ + 4k̂ and b = ĵ – k̂, then find a unit vector perpendicular to (a + b) and (a – b).
Q37
long answer
4 marks
Camphor is a waxy, colourless solid with strong aroma that evaporates through the process of sublimation, if left in the open at room temperature. A cylindrical camphor tablet whose height is equal to its radius (r) evaporates when exposed to air such that the rate of reduction of its volume is proportional to its total surface area. Thus, dV/dt = kS is the differential equation, where V is the volume, S is the surface area and k is a constant.
Q37
long answer
Camphor is a waxy, colourless solid with strong aroma that evaporates through the process of sublimation, if left in the open at room temperature. (Cylindrical-shaped Camphor tablets)
A cylindrical camphor tablet whose height is equal to its radius (r) evaporates when exposed to air such that the rate of reduction of its volume is proportional to its total surface area. Thus, dV/dt = kS is the differential equation, where V is the volume, S is the surface area and t is the time in hours.
Based upon the above information, answer the following questions:
(i) Write the order and degree of the given differential equation.
(ii) Substituting V = πr³ and S = 2πr², we get the differential equation dr/dt = (2k)/3. Solve it, given that r(0) = 5 mm.
(iii) (a) If it is given that r = 3 mm when t = 1 hour, find the value of k. Hence find t for r = 0 mm.
OR
(iii) (b) If it is given that r = 1 mm when t = 1 hour, find the value of k. Hence, find t for r = 0 mm.
Q38
long answer
Based upon the results of regular medical check-ups in a hospital, it was found that out of 1000 people, 700 were very healthy, 200 maintained average health and 100 had a poor health record.
Let A1: People with good health, A2: People with average health, and A3: People with poor health.
During a pandemic, the data expressed that the chances of people contracting the disease from category A1, A2 and A3 are 25%, 35% and 50%, respectively.
Based upon the above information, answer the following questions:
(i) A person was tested randomly. What is the probability that he/she has contracted the disease?
(ii) Given that the person has not contracted the disease, what is the probability that the person is from category A2?