Grade-12,PB-1,Edited
Grade-12,PB-1,Edited
Grade-12,PB-1,Edited
x −1 −1 x −1 x −1 x
(a) cosec (b) sec (c) cosec (d) cos
a a a a
−1 −1
4. tan ¿ ¿ - sec ¿ is equal to
π
(a) π (b)−π (c) (d) None of these
3
5. Suppose P, Q and R are different matrices of order 3 × 5, a × b and c x d respectively, then value
of ac + bd is, if matrix 2P + 3Q – 4R is defined
(a) 9 (b) 30 (c) 34 (d) None of these
6. ∫ ¿ ¿ ¿ = …….
x x x x
(a) 10 −10 +c (c)
10 +10 +c
−1
( b ) ( 10 x + x 10) + c (d) log ( x 10 +10x ) + c
x
e (1+ x)
7.∫ dx
cos 2 (x e x )
(a)−cot ( e x x ) + c (c) tan ( x e x ) +c
( b ) tan ( e x ) +c (d) None of these
8. The function f(x)= ax + b is strictly decreasing for all x∈R iff:
(a) a=0 (b) a<0 (c) a>0 (d) None of these
9. A cylindrical vessel of radius 0.5 m is filled with oil at the rate of 0.25 π cubic metre/min. The rate
at which oil is rising is
(a)1m/min (b)2m/min (c)5m/min (d)None of these
( )
2 2
dy d y
10. The order and degree of the differential equation + 4 2 + 5=0 is
dx d x
(a) order 1 and degree 2 (b) order 2 and degree 2
(c) order 2 and degree 1 (d) order 1 and degree 1
dy y 2
11. The Integrating Factor of the differential equation − =2 x is
dx x
−1 1
(a) x 2 (b) x (c) (d)
x x
2
12. The area bounded by the parabola y =36 x and the line x = 1 above the x-axis is ______ sq units.
(a) 2 (b) 4 (c) 6 (d) None of these
13. For an L.P.P. the objective function is Z = 4x + 3y, and the feasible region determined by a set of
constraints (linear inequations) is shown in the graph.
14. If A is a square matrix of order 3 such that |A| = - 5 , then value of |− A A' ∨¿ is
(a) 125 (b) – 125 (c) 25 (d) – 25
15. If the corner points of the feasible region are determined by the following system of linear
inequalities: 2x + y ≤ 10, x + 3y ≤ 15, x, y ≥ 0 are (0,0), (5,0), (3,4), (0,5) and Z= px + qy, where p,q > 0.
Condition on p and q so that the maximum of Z occurs at both (3,4) and (0,5) is
(a) p = q (b) p = 2q (c) p = 3q (d) q = 3p
dy
16. If y = I sinx -cosx I then at x= π /6 is
dx
(a)0 (b)-1 (c)1 (d) None of these
17. If A is a non-singular matrix of order 3 and |A| = – 4, find |adj A|.
1
(a) 4 (b) 16 (c) 64 (d)
4
π /2
18. ∫ log ( cotx ) dx=…
0
(a) π /4 log tanx (b) π /8 log 2 (c) 0 ( d ) π /8 log 8
In the following questions 19 and 20, a statement of assertion (A) is followed by a statement of
reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true, and Reason(R) is the correct explanation of Assertion
(A).
(b) Both Assertion (A) and Reason (R) are true, but Reason(R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true, but Reason (R) is false.
(d) Assertion (A) is false, but Reason (R) is true.
(x−3) x
25. Find ∫ e dx
( x −1)3
SECTION C
π
2
26. Evaluate:
∫ ( 2 log sin x−log sin 2 x ) dx
0
[ ]
1 −1 1
33. Determine the inverse 2 1 −3 and hence use it to solve the equations
1 1 1
𝑥 + 2𝑦 + 𝑧 = 4; −¿𝑥 + 𝑦 + 𝑧 = 0 ; 𝑥 −¿ 3𝑦 + 𝑧 = 2.
34. Show that the relation R in the set N of Natural numbers given by R = {(a, b ): |a - b| is a multiple
of 4 } is an equivalence relation.
OR
d ∈ N}. Prove that R is an equivalence relation and obtain the equivalence class [(2, 5)].
Let R be a relation defined in N × N defined by: R = {(a, b) R (c, d) if and only if a +d = b + c and a, b, c,
x 1− y z−2
35. Find the co-ordinates of image of the point (1,6,3) in the line = = .
1 2 3
SECTION E
36. Case-Study 1: Read the following passage and answer the questions given below.
Rohan, a student of class XII, visited his uncle’s flat with his father.
His observations:
Window of the house is in the form of a rectangle surmounted by a
semicircular opening. The perimeter of this window is 10 m (refer fig.)
(i)If x and y represent the length and breadth of the rectangular region of the
window, then find the relation between x and y.
(ii) Express area of the window in terms of x (alone).
(iii) Find the value of x for maximizing the Area (A) of this window.
(iv) Find the maximum area of the window.
OR
(iv) For maximum value of A, find the breadth of the rectangular part of the
window.
37. Observe the diagram shown alongside in which two lines l 1∧l 2 are shown in space and AB is the
only line which is perpendicular to both the lines l 1∧l 2 .