Class XII Math Pre-Board Blueprint 2024
Class XII Math Pre-Board Blueprint 2024
General Instructions:
(i) All the questions are compulsory.
2 3 𝑑𝑥 1
The value of ∫0 is
√9−𝑥 2
𝜋 𝜋 𝜋 𝜋
(a) 6 (b) 4 (c) 2 (d) 18
OR
(1+𝑥2 )
The value of ∫ 𝑥𝑒 𝑑𝑥 is
2 2 2
𝑒 (1+𝑥 ) 𝑒 (1+𝑥 ) 𝑒 (1+𝑥 )
(a) +c (b) +c (c) +c
2 3 4
2
𝑒 (1−𝑥 )
(d) +c
2
3 2 1
𝑑2𝑦
The difference of the order and the degree of the differential equation ( 2) +
𝑑𝑥
𝑑𝑦 3 4
(𝑑𝑥 ) + 𝑥 = 0 is :
(a) 1 (b) 2 (c) -1 (d) 0
OR
𝑑𝑦
Degree of the differential equation sin 𝑥 + cos (𝑑𝑥 ) = 𝑦 2 is
(a) 2 (b) 1 (c) not defined (d) 0
4 If 𝛼, 𝛽 𝑎𝑛𝑑 𝛾 are the angles which a half ray makes with the positive direction of 1
the axes, then 𝑠𝑖𝑛 2 𝛼 + 𝑠𝑖𝑛2 𝛽 + 𝑠𝑖𝑛2 𝛾 is equal to
(a) 1 (b) 2 (c) 0 (d) -1
5 1
Based on the given shaded region as the feasible region in the graph, at
which point(s) is the objective function Z = 3x + 9y maximum?
(a)Point B (b) Point C (c) Point D (d) every point on the line segment CD
6 The corner points of the bounded feasible region of an LPP are 1
O(0, 0), A(250, 0), B(200, 50) and C(0, 175). If the maximum value of the
objective function Z = 2ax+ by occurs at the points A(250, 0) and B(200, 50),
then the relation between a and b is:
19. 1 3 𝜆+2 1
Assertion (A) : If matrix 𝐴 = [2 4 8 ] is singular then 𝜆 = 4.
3 5 10
Reason (R) : If A is a singular matrix, then |𝐴| = 0.
20. 1 2 𝑑𝑦 2 1
Assertion: If 𝑦 = 4 𝑢 4 and 𝑢 = 3 𝑥 3 + 5, then 𝑑𝑥 = 3 𝑥 2 (2𝑥 3 + 15)3.
𝑑𝑦 𝑑𝑦 𝑑𝑢
Reason: If y is a function of 𝑢 and 𝑢 is a function of 𝑥, then 𝑑𝑥 = 𝑑𝑢 × 𝑑𝑥 .
a) Both A and R are true and R is the correct explanation of A.
22. 2
The radius r of a right circular cylinder is decreasing at the rate of
7 3 cm/min.
and its height h is increasing at the rate of 2 cm/min. When r = 7 cm and h
= 2 cm, find the rate of change of the volume of cylinder.
OR
Find the absolute maximum value and the absolute minimum value of the
1 9
function: 𝑓(𝑥) = 4𝑥 − 2 𝑥 2 , 𝑥 ∈ [−2, 2]
23. 𝑑𝑥 2
Evaluate ∫ .
𝑥 2 +4𝑥+8
24. . If 𝜃 is the angle between two vectors i − 2j + 3k and 3i − 2j + k, find sin 𝜃. 2
25. 2
If 𝑎 is a unit vector, then find |𝑥 | if (𝑥 − 𝑎)(𝑥 + 𝑎) = 8
Section C
26. Show that the relation R defined by (a, b) R (c, d) ⇒ a + d = b + c 3
on the set N × N is an equivalence relation.
OR
Show that the relation R in the set A = {1, 2, 3, 4, 5} given by R = {(a, b) : |a – b|
is even}, is an equivalence relation.
27. 3
𝑑2𝑦
If x = a (cos 2t + 2t sin 2t) and = a (sin 2t − 2t cos 2t), then find 𝑑𝑥 2.
30. 1 3
Evaluate I= ∫ 1+𝑐𝑜𝑡𝑥 𝑑𝑥
31. 3
If A and B are two independent events such that P(A’∩ 𝐵)= 5/12 and P(A ∩ 𝐵′)=
1/6. Then find P(A) - P(B)
Section D
32. 1 −1 0 2 2 −4 5
Determine the product [3 3 4] [−4 2 −4], and use it to solve the
0 1 2 2 −1 5
system of equations:
𝑥 − 𝑦 = 3, 2𝑥 + 3𝑦 + 4𝑧 = 17, 𝑦 + 2𝑧 = 7.
33. 𝟐𝒙 5
Find : I = ∫ (𝒙𝟐+𝟏)(𝒙𝟐+𝟑) 𝑑𝑥
OR
𝜋
𝑠𝑖𝑛𝑥+𝑐𝑜𝑠𝑥
4
Find I =∫0 𝑑𝑥
16+9𝑠𝑖𝑛2𝑥
34. Find the area of region bounded by the parabola 4𝑥 2 = 𝑦 and the line y= 5
8x + 12.
OR
Using integration, find the area of the region bounded by the triangle whose
vertices are A(2,5), B(4, 7) and C(6,2).
35. Find the shortest distance between the lines 𝑟 = (3𝑖̂ + 2𝑗̂ − 4𝑘̂) + 𝜆(𝑖̂ + 2𝑗̂ + 2𝑘̂) 5
and 𝑟 = (5𝑖̂ − 2𝑗̂) + 𝜇(3𝑖̂ + 2𝑗̂ + 6𝑘̂) .
Iflines intersect, find their point of intersection.
Section E
(Attempt any four parts out of five)
36. A gardener wants to construct a rectangular bed of garden in a circular patch of 4
land. He takes the maximum perimeter of the rectangular region as possible.
(Refer to the images given below for calculations)
(i) Find the perimeter of rectangle in terms of any one side and radius of
circle.
(ii) Find critical points to maximize the perimeter of rectangle?
(iii) Check for maximum or minimum value of perimeter at critical point.
OR
If a rectangle of the maximum perimeter which can be inscribed in a circle of
radius 10 cm is square, then the perimeter of region.
37. 4
Two men on either side of a temple of 30 meters high observe its top at the angle
of elevation 𝛼 and𝛽 respectively (as shown in the figure below). The distance
between the two men is 40√3 meters and the distance between the first person A
and the temple is 30√3 meters.
Marking scheme
1. 1 1
(b) 2
2
2. 𝜋 𝑒 (1+𝑥 ) 1
(c) 2 OR (c) 2 +c
3. (d) 0 OR (c) not defined 1
4. (b) 2 1
5. (d) every point on the line segment CD 1
6. (a) 2a=b 1
7. (a) 1 1
4
8. (c) Discontinuous exactly at three point 1
9. (c)log 𝑥 1
10. (b) 2 1
√7
11. (b) 𝜋 1
4
12. (d) −2 , 3 , −6 1
7 7 7
13. (c) √7 1
14. (b) 2 × 2 1
15. (c) 𝑥 2 + 𝑦 2 = 13 1
3
16. (a) cos 𝑦−2 1
17. (b)zero matrix 1
18. (b)reflexive, transitive but not symmetric 1
19. (a) 1
20. (d) 1
𝜋
21. Since f(x) is cont. at 𝑥 = − 6 , hence
𝜋 1
L.HL.=R.H.L. =f( − 6 )
Solving for k , get k = 2 1
OR
f’(x) =4-x , x=4
f(4)=8 , f(-2)= -10, f(9/2)= 7.8
23. 𝑑𝑥 𝑑𝑥 1
∫ 2 =∫
𝑥 + 4𝑥 + 8 (𝑥 + 2)2 + 4 1
1 𝑥+2
= 2 tan−1 ( 2 ) + 𝐶
⃗⃗⃗ 𝑏⃗ = |𝑎.
24. To write 𝑎. ⃗⃗⃗ ||𝑏⃗ | sin 𝜃 𝑛̂ 1
2√6
To find value of sin 𝜃 = 1
7
25. To write |𝑎| = 1 1
To find |𝑥 | = 3 1
26. To show that 1
R is reflexive 1
R is symmetric 1
R is transitve
27. To find 𝑑𝑥 and 𝑑𝑦 1
𝑑𝑡 𝑑𝑡
𝑑𝑦 1
𝑑𝑦 𝑑𝑡
To write = 𝑑𝑥 = tan2t
𝑑𝑥
𝑑𝑡
𝑑2𝑦 1 1
2
= 𝑠𝑒𝑐 3 2𝑡
𝑑𝑥 2𝑡𝑎
28. To find I.F. =e2x 1
−5 1
y = 4 e-3x +c e-2x
29. Plotting three lines correctly 1
Shading the feasible region 1
Minimize Z = 300 at (60, 0) 1
30. I= ∫ 1 𝑑𝑥
1+𝑐𝑜𝑡𝑥
1
=∫ 𝑐𝑜𝑠𝑥 𝑑𝑥
1+
𝑠𝑖𝑛𝑥
𝑠𝑖𝑛𝑥
=∫ 𝑠𝑖𝑛𝑥 + 𝑐𝑜𝑠𝑥 𝑑𝑥
1 2𝑠𝑖𝑛𝑥
= 2 ∫ 𝑠𝑖𝑛𝑥 + 𝑐𝑜𝑠𝑥 𝑑𝑥 1
1 (𝑠𝑖𝑛𝑥+𝑐𝑜𝑠𝑥)+𝑠𝑖𝑛𝑥− 𝑐𝑜𝑠𝑥)
= 2∫ 𝑑𝑥
𝑠𝑖𝑛𝑥 + 𝑐𝑜𝑠𝑥
1 1 𝑠𝑖𝑛𝑥−𝑐𝑜𝑠𝑥
= 2 ∫ 1𝑑𝑥 + ∫ 𝑑𝑥
2 𝑠𝑖𝑛𝑥 + 𝑐𝑜𝑠𝑥
1 1 𝑠𝑖𝑛𝑥−𝑐𝑜𝑠𝑥 1
= 2 𝑥 + 2 ∫ 𝑠𝑖𝑛𝑥 + 𝑐𝑜𝑠𝑥 𝑑𝑥
Let sinx + cosx = t ⇒ (cosx - sinx)dx = dt
1 1 −1
= 2 𝑥 + 2 ∫ 𝑡 𝑑𝑡
1 1
= 2𝑥 - log |𝑡| + c
2
1 1
= 2𝑥 - log |𝑠𝑖𝑛𝑥 + 𝑐𝑜𝑠𝑥| + c 1
2
32. 1− 1 0 2 2 −4
𝐴𝐵 = [ 3 3 4] [−4 2 −4]
0 1 2 2 −1 5 1
6 0 0
= [0 6 0]
0 0 6
1 0 0
=6 [0 1 0] 1
0 0 1
AB = 6I
1
A-1 = 6 𝐵 1
2 2 −4
1
= = [−4 2 −4]
6
2 −1 5 1
Writing given equation in matrix form
1 −1 0 𝑥 3
[3 3 4] [𝑦] = [17]
0 1 2 𝑧 7
A X = C
1
X = A-1 C = 6 𝐵𝐶 1
𝑥 2 2 −4 3
1
𝑦
[ ] = 6 [−4 2 −4] [17]
𝑧 2 −1 5 7
12
1
= 6 [−6]
24
2
= [−1]
4
33. I = ∫ 𝟐𝒙
𝑑𝑥
(𝒙𝟐 +𝟏)(𝒙𝟐 +𝟑)
Let, x2 = t
2xdx = dt,
𝟏
I = ∫ (𝒕+𝟏)(𝒕+𝟑) 𝑑𝑡
𝑑𝑡 1
= ∫ (𝑡+1)(𝑡+3)
1 𝑨 𝑩
Let, (𝑡+1)(𝑡+3) = 𝒕+𝟏 + 𝒕+𝟑
1
1 = A(t+3) + B(t+1)
Equating the coefficients of t and the constant term, we get
A+B = 0
3A + B = 1
On solving these equations, we get
1
A = 1/2 , B = -1/2
1 𝟏/𝟐 −𝟏/𝟐
= + 𝒕+𝟑
(𝑡+1)(𝑡+3) 𝒕+𝟏
𝑑𝑡 1/2 −1/2
∫ (𝑡+1)(𝑡+3) = ∫ 𝑡+1 𝑑𝑡 +∫ 𝑡+3
𝑑𝑡
1 1
= log|t+1| - log|t+3| + c
2 2
1 𝑡+1 1
= log| |+c
2 𝑡+3
1 𝒙𝟐 +𝟏
= 2log|𝒙𝟐+𝟑| + c
OR 1
𝜋
𝑠𝑖𝑛𝑥+𝑐𝑜𝑠𝑥
I=∫04 𝑑𝑥
16+9𝑠𝑖𝑛2𝑥
0 1
=∫−1 𝑑𝑡
16+9(1−𝑡 2) 1
0 1
=∫−1 𝑑𝑡
25− 9𝑡 2
1
=15 𝑙𝑜𝑔2
2
34. Given parabola 4𝑥 2 = 𝑦 and the line y = 8x + 12
OR
Using integration, find the area of the region bounded by the triangle
whose vertices are A(2,5), B(4, 7) and C(6,2).
Sol.: Equation of line passing through two points (x1, y1) and (x2, y2) is
given by
𝑦2−𝑦1
y-y1 = ( x2−x1 )(𝑥 − 𝑥1)
35. 𝑎
⃗⃗⃗⃗2 − ⃗⃗⃗⃗
𝑎1=2𝑖 ̂ − 4𝑗̂ + 4𝑘̂
⃗⃗⃗
𝑏1 × ⃗⃗⃗⃗𝑏2 = 8𝑖̂ − 4𝑘̂ 1
(𝑏 ⃗⃗⃗1 × ⃗⃗⃗⃗
𝑏2 ).( ⃗⃗⃗⃗
𝑎2 − ⃗⃗⃗⃗
𝑎1 ) = 16-16=0
Hence lines are intersecting and the S.D. between lines is 0 2
For point of intersection
𝑟 = (3𝑖̂ + 2𝑗̂ − 4𝑘̂ ) + 𝜆(𝑖̂ + 2𝑗̂ + 2𝑘̂ ) = (5𝑖̂ − 2𝑗̂) + 𝜇(3𝑖̂ + 2𝑗̂ + 6𝑘̂)
Get here 𝜆= - 4, 𝜇= - 2
𝑟 = (3𝑖̂ + 2𝑗̂ − 4𝑘̂ ) + (−4)(𝑖̂ + 2𝑗̂ + 2𝑘̂) =(−𝑖̂ − 6𝑗̂ − 12𝑘̂) 1
point of intersection is (-1, -6 , -12)
1
36. (i) Perimeter =2(𝑥 + √4𝑎2− 𝑥2) 1
(ii) 𝑥 = √2𝑎 2
(iii) To show that 𝑥 = √2𝑎 is point of maxima 1
37. 1 1
(i) 𝛼 = sin−1 (2)
1
(ii) 𝛽 = tan−1 √3 2
𝜋
(iii) ∠𝐴𝐵𝐶 ≠ 6
𝑂𝑅
Domain=[-1 , 1], Range=[0 , 𝜋]
38. (i). P(E) = 0.38 2
𝐸 7 2
(ii) 𝑃 ( 𝐸3) = 19